Selectively adjustable cardiac valve implants

ABSTRACT

Methods and devices are provided for support of a body structure. The devices can be adjusted within the body of a patient in a minimally invasive or non-invasive manner such as by applying energy percutaneously or external to the patient&#39;s body. The energy may include, for example, acoustic energy, radio frequency energy, light energy and magnetic energy. Thus, as the body structure changes size and/or shape, the size and/or shape of the annuloplasty rings can be adjusted to provide continued reinforcement. In certain embodiments, the devices include a first body member including a first shape memory material configured to transform the annuloplasty ring from a first configuration having a first size of a dimension to a second configuration having a second size of the dimension. The second size is less than said first size in septal lateral distance. The devices also include a second body member including a second shape memory material configured to transform the annuloplasty ring from the second configuration to a third configuration having a third size of the dimension, wherein the second size is less than the third size in septal lateral distance.

RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §120 as acontinuation application of U.S. patent application Ser. No. 11/123,891filed on May 6, 2005 which claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Application No. 60/584,432, filed Jun. 29, 2004. Bothaforementioned priority applications are hereby incorporated byreference herein in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to methods and devices for reinforcingdysfunctional heart valves and other body structures. More specifically,the present invention relates to annuloplasty rings that can be adjustedwithin the body of a patient.

2. Description of the Related Art

The circulatory system of mammals includes the heart and theinterconnecting vessels throughout the body that include both veins andarteries. The human heart includes four chambers, which are the left andright atrium and the left and right ventricles. The mitral valve, whichallows blood flow in one direction, is positioned between the leftventricle and left atrium. The tricuspid valve is positioned between theright ventricle and the right atrium. The aortic valve is positionedbetween the left ventricle and the aorta, and the pulmonary valve ispositioned between the right ventricle and pulmonary artery. The heartvalves function in concert to move blood throughout the circulatorysystem. The right ventricle pumps oxygen-poor blood from the body to thelungs and then into the left atrium. From the left atrium, the blood ispumped into the left ventricle and then out the aortic valve into theaorta. The blood is then recirculated throughout the tissues and organsof the body and returns once again to the right atrium.

If the valves of the heart do not function properly, due either todisease or congenital defects, the circulation of the blood may becompromised. Diseased heart valves may be stenotic, wherein the valvedoes not open sufficiently to allow adequate forward flow of bloodthrough the valve, and/or incompetent, wherein the valve does not closecompletely. Incompetent heart valves cause regurgitation or excessivebackward flow of blood through the valve when the valve is closed. Forexample, certain diseases of the heart valves can result in dilation ofthe heart and one or more heart valves. When a heart valve annulusdilates, the valve leaflet geometry deforms and causes ineffectiveclosure of the valve leaflets. The ineffective closure of the valve cancause regurgitation of the blood, accumulation of blood in the heart,and other problems.

Diseased or damaged heart valves can be treated by valve replacementsurgery, in which damaged leaflets are excised and the annulus issculpted to receive a replacement valve. Another repair technique thathas been shown to be effective in treating incompetence is annuloplasty,in which the effective size of the valve annulus is contracted byattaching a prosthetic annuloplasty repair segment or ring to aninterior wall of the heart around the valve annulus. The annuloplastyring reinforces the functional changes that occur during the cardiaccycle to improve coaptation and valve integrity. Thus, annuloplastyrings help reduce reverse flow or regurgitation while permitting goodhemodynamics during forward flow.

Generally, annuloplasty rings comprise an inner substrate of a metalsuch as stainless steel or titanium, or a flexible material such assilicon rubber or Dacron®. The inner substrate is generally covered witha biocompatible fabric or cloth to allow the ring to be sutured to theheart tissue. Annuloplasty rings may be stiff or flexible, may be openor closed, and may have a variety of shapes including circular,D-shaped, or C-shaped. The configuration of the ring is generally basedon the shape of the heart valve being repaired or on the particularapplication. For example, the tricuspid valve is generally circular andthe mitral valve is generally D-shaped. Further, C-shaped rings may beused for tricuspid valve repairs, for example, because it allows asurgeon to position the break in the ring adjacent the atrioventricularnode, thus avoiding the need for suturing at that location.

Annuloplasty rings support the heart valve annulus and restore the valvegeometry and function. Although the implantation of an annuloplasty ringcan be effective, the heart of a patient may change geometry over timeafter implantation. For example, the heart of a child will grow as thechild ages. As another example, after implantation of an annuloplastyring, dilation of the heart caused by accumulation of blood may ceaseand the heart may begin returning to its normal size. Whether the sizeof the heart grows or reduces after implantation of an annuloplastyring, the ring may no longer be the appropriate size for the changedsize of the valve annulus.

SUMMARY OF THE INVENTION

Thus, it would be advantageous to develop systems and methods forreinforcing a heart valve annulus or other body structure using anannuloplasty device that can be adjusted within the body of a patient ina minimally invasive or non-invasive manner. In an embodiment, anadjustable annuloplasty device includes a body member configured toconform at least partially to a cardiac valve annulus. The body memberincludes a shape memory material configured to transform from a firstshape to a second shape in response to being heated. The annuloplastydevice further includes a thermally insulative material at leastpartially covering said body member and a thermally conductive materialextending into said thermally insulative material. The thermallyconductive material is configured to communicate thermal energy to thebody member. The thermally conductive material can be configured as animaging marker and can include a radiopaque material. The annuloplastydevice further includes a suturable material at least partially coveringsaid thermally insulative material. The thermally conductive materialcan be disposed at least partially over said suturable material and canprovide indicia of one or more valve commissure locations after saidannuloplasty device is implanted on or near a heart valve annulus. Thethermally conductive material can include at least one of a metallicwire or a metallic ribbon and the body member can be selected from avariety of shapes including, for example, ring shaped, C-shaped andD-shaped.

In another embodiment, an adjustable annuloplasty device includes a bodymember configured to conform at least partially to a cardiac valveannulus. The body member includes a shape memory material configured totransform from a first shape to a second shape in response to beingheated. The annuloplasty device further includes a thermally conductivemember adjacent said body member, said thermally conductive materialconfigured to communicate thermal energy to said body member. Thethermally conductive member can be further configured as an imagingmarker and may include a radiopaque material. The annuloplasty devicemay further include a suturable material at least partially coveringsaid body member. The thermally conductive member can be disposed atleast partially over said suturable material and the thermallyconductive member can provide indicia of one or more valve commissurelocations after said adjustable annuloplasty device is implanted on ornear a heart valve annulus. The thermally conductive member can includeat least one of a metallic wire or a metallic ribbon, and the bodymember may be selected from a variety of shapes including, for example,ring shaped, C-shaped and D-shaped.

In another embodiment, an adjustable annuloplasty device includes a bodymember having a material that exhibits a ferromagnetic shape memoryeffect. The body member has a first size of a dimension of said devicein a first configuration and a second size of said dimension of saiddevice in a second configuration. The body member is configured to beimplanted into a heart so as to reinforce a cardiac valve annulus insaid first configuration. The body member is configured to transformfrom said first configuration to said second configuration in vivo inresponse to a magnetic field inducing said ferromagnetic shape memoryeffect. The body member in said second configuration is configured toreduce a size of said cardiac valve annulus. The shape memory materialmay include at least one of Fe—C, Fe—Pd, Fe—Mn—Si, Co—Mn, Fe—Co—Ni—Ti,Ni—Mn—Ga, Ni₂MnGa, and Co—Ni—Al. The body member can be configured totransform from said first configuration to said second configurationwithout substantially changing the temperature of said ferromagneticshape memory material. The device can have a ring shape, a C-shape, aD-shape, or other shape.

In another embodiment, an adjustable annuloplasty device includes a bodymember including a shape memory material and an energy absorptionenhancement material configured to absorb energy in response to a firstactivation energy. The energy absorption enhancement material is inthermal communication with said shape memory material. The body memberhas a first size of a body dimension in a first configuration and asecond size of said body dimension in a second configuration. The bodymember is configured to be implanted in said first configuration into aheart. The body member is configured to transform from said firstconfiguration to said second configuration in response to said firstactivation energy. The second configuration is configured to reduce adimension of a cardiac valve annulus in said heart. The energyabsorption enhancement material may be further configured to heat inresponse to said first activation energy and may be configured totransfer heat to said shape memory material.

The shape memory material can include at least one of a metal, a metalalloy, a nickel titanium alloy, a shape memory polymer, polylactic acid,and polyglycolic acid. The annuloplasty device may further include anelectrically conductive material configured to conduct a current inresponse to said first activation energy and to transfer thermal energyto said shape memory material. The annuloplasty device may furtherinclude a suturable material configured to facilitate attachment of saidbody member to said cardiac valve annulus. The body member can have athird size of said body dimension in a third configuration, wherein saidthird size is larger than said second size, and wherein said body memberis configured to transform to said third configuration in response to asecond activation energy to increase said dimension of said cardiacvalve annulus. The body member can have a third size of said bodydimension in a third configuration, wherein said third size is smallerthan said second size, and wherein said body member is configured totransform to said third configuration in response to a second activationenergy to decrease said dimension of said cardiac valve annulus. Theenergy absorption enhancement material can include a nanoparticle thatmay include, for example, at least one of a nano shell and a nanosphere.The energy absorption enhancement material can be radiopaque.

In another embodiment, an adjustable annuloplasty ring includes atubular member configured to be attached to or near a cardiac valveannulus. The tubular member includes a receptacle end and an insert endconfigured to couple with said receptacle end of said tubular membersuch that said tubular member substantially forms a shape of a ring. Theinsert end is configured to move with respect to said receptacle end tochange a circumference of said ring. The tubular member can furtherinclude a shape memory material configured to change, after implantationin a patient's body, from a first shape to a second shape in response toan activation energy, wherein said shape change causes said change inthe circumference of said ring. The tubular member can further includean energy absorption enhancement material disposed within said tubularmember. The energy absorption enhancement material facilitates transferof heat to said shape memory material. The energy absorption enhancementmaterial can be further disposed on an outer surface of said tubularmember. The tubular member can further include a ratchet memberconfigured to allow said insert end to move predominantly in a firstdirection with respect to said receptacle end, and to resist movement ina second, opposite direction. The annuloplasty ring can be ring shaped,C-shaped, D-shaped, or another shape.

In another embodiment, an adjustable annuloplasty ring includes a bodymember configured to be attached to or near a cardiac valve annulus. Thebody member includes a first end and a second end configured to couplewith said first end of said body member such that said body membersubstantially forms a shape of a ring. The second end is configured tomove with respect to said first end to change a circumference of saidring. The body member can further include a shape memory materialconfigured to change, after implantation in a patient's body, from afirst shape to a second shape in response to an activation energy,wherein said shape change causes said change in the circumference ofsaid ring. The body member can further include an energy absorptionenhancement material that facilitates transfer of heat to said shapememory material. The body member can further include a ratchet memberconfigured to allow said second end to move predominantly in a firstdirection with respect to said first end, and to resist movement in asecond, opposite direction. The annuloplasty ring can be ring shaped,C-shaped, D-shaped, or another shape.

In another embodiment, an adjustable annuloplasty ring includes a firstshape memory member configured to transform said annuloplasty ring froma first configuration having a first size of a ring dimension to asecond configuration having a second size of the ring dimension. Thesecond size is less than said first size. The ring also includes asecond shape memory member configured to transform said annuloplastyring from said second configuration to a third configuration having athird size of the ring dimension. The second size is less than saidthird size. The first shape memory member can be configured to changeshape in response to being heated to a first temperature and the secondshape memory member can be configured to change shape in response tobeing heated to a second temperature. The first temperature can be lowerthan said second temperature or the second temperature can be lower thansaid first temperature. At least one of said first shape memory memberand said second shape memory member can include at least one of a metal,a metal alloy, a nickel titanium alloy, a shape memory polymer,polylactic acid, and polyglycolic acid. At least one of said first shapememory member and said second shape memory member can be configured tochange shape in response to a magnetic field. At least one of said firstshape memory member and said second shape memory member can include atleast one of Fe—C, Fe—Pd, Fe—Mn—Si, Co—Mn, Fe—Co—Ni—Ti, Ni—Mn—Ga,Ni₂MnGa, and Co—Ni—Al. The ring dimension can be a septolateraldimension.

In another embodiment, an adjustable annuloplasty ring includes a firstshape memory member configured to transform said annuloplasty ring froma first configuration having a first size of a ring dimension to asecond configuration having a second size of the ring dimension, whereinsaid second size is less than said first size, and a second shape memorymember configured to transform said annuloplasty ring from said secondsize to a third size of the ring dimension, wherein said third size isless than said second size.

In another embodiment, an adjustable annuloplasty ring includes a firstshape memory member configured to transform said annuloplasty ring froma first configuration having a first size of a ring dimension to asecond configuration having a second size of the ring dimension, whereinsaid first size is less than said second size, and a second shape memorymember configured to transform said annuloplasty ring from said secondconfiguration to a third configuration having a third size of the ringdimension, wherein said third size is less than said second size.

In another embodiment, an adjustable annuloplasty ring includes a firstshape memory member configured to transform said annuloplasty ring froma first configuration having a first size of a ring dimension to asecond configuration having a second size of the ring dimension, whereinsaid first size is less than said second size, and a second shape memorymember configured to transform said annuloplasty ring from said secondconfiguration to a third configuration having a third size of the ringdimension, wherein said second size is less than said third size.

In another embodiment, an annuloplasty device configured to support aheart valve includes an anterior portion, a posterior portion, and twolateral portions corresponding to intersections of said anterior portionand said posterior portion. The annuloplasty device has a first shape ina first configuration and a second shape in a second configuration. Theannuloplasty device is configured to transform from said firstconfiguration to said second configuration in response to a firstactivation energy applied thereto. The transformation is configured toreduce a distance between said anterior portion and said posteriorportion without substantially decreasing a distance between said twolateral portions. The annuloplasty device can also include one or moreimaging markers that can include, for example, radiopaque markers. Thetransformation can be further configured to increase said distancebetween said two lateral portions.

In another embodiment, the annuloplasty device further includes a wirethat extends at least partially along said anterior and posteriorportions, and a first shape memory member at least partially covering orcontacting said wire. The wire can be selected from the group consistingof a round wire, a flat wire, a mesh wire, a rod-shaped wire, and aband-shaped wire. The first shape memory member can include a tubularstructure, wherein at least a portion of said wire passes through saidtubular structure. The tubular structure can include a first shapememory body configured to respond to said first activation energy bybending said wire such that said annuloplasty device transforms fromsaid first shape to said second shape.

The tubular structure can further include a second shape memory bodyconfigured to respond to a second activation energy by bending said wiresuch that said annuloplasty device transforms from said second shape toa third shape. The annuloplasty device in said third shape can have areduced distance between said anterior portion and said posteriorportion as compared to said second shape. Alternatively, theannuloplasty device in said third shape can have an increased distancebetween said anterior portion and said posterior portion as compared tosaid second shape. At least one of said first activation energy and saidsecond activation energy can include a magnetic field, acoustic energy,radio frequency energy. In certain embodiments, the first shape memorybody can change to a first activation temperature in response to saidfirst activation energy, wherein said second shape memory body changesto a second activation temperature in response to said second activationenergy. The first activation temperature can be lower than said secondactivation temperature.

In certain embodiments, the annuloplasty device further includes a firstshape memory band that extends at least partially along said anteriorand posterior portions. The first shape memory band loops back on itselfin a curvilinear configuration such that portions of said first shapememory band overlap one another. The first shape memory band can beconfigured to change its length in response to said first activationenergy such that said overlapping portions slide with respect to oneanother to change said annuloplasty device from said first configurationto said second configuration. The annuloplasty device can furtherinclude a second shape memory band at least partially disposed betweenor adjacent to said overlapping portions of said first shape memoryband. The second shape memory band can be configured to respond to asecond activation energy to transform said annuloplasty device from saidsecond configuration to a third configuration. The annuloplasty devicein said third configuration can have a reduced distance between saidanterior portion and said posterior portion as compared to said secondshape. Alternatively, the annuloplasty device in said thirdconfiguration can have an increased distance between said anteriorportion and said posterior portion as compared to said second shape. Atleast one of said first activation energy and said second activationenergy can include a magnetic field, acoustic energy, radio frequencyenergy, or another form of energy. The first shape memory band canchange to a first activation temperature in response to said firstactivation energy, wherein said second shape memory band changes to asecond activation temperature in response to said second activationenergy.

In another embodiment, an annuloplasty device changes a patient'scardiac valve annulus size in an anteroposterior dimension withoutsubstantially changing said annulus in a lateral dimension. The changingoccurs in response to a transmission of energy from a non-invasivesource external to the patient's heart to said annuloplasty device.

For purposes of summarizing the invention, certain aspects, advantagesand novel features of the invention have been described herein. It is tobe understood that not necessarily all such advantages may be achievedin accordance with any particular embodiment of the invention. Thus, theinvention may be embodied or carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other advantages as may be taught or suggestedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

Systems and methods which embody the various features of the inventionwill now be described with reference to the following drawings:

FIG. 1A is a top view in partial section of an adjustable annuloplastyring according to certain embodiments of the invention;

FIG. 1B is a side view of the annuloplasty ring of FIG. 1A;

FIG. 1C is a transverse cross-sectional view of the annuloplasty ring ofFIG. 1A;

FIG. 2 is a graphical representation of the diameter of an annuloplastyring in relation to the temperature of the annuloplasty ring accordingto certain embodiments of the invention;

FIG. 3A is a top view in partial section of an adjustable annuloplastyring having a D-shaped configuration according to certain embodiments ofthe invention;

FIG. 3B is a side view of the annuloplasty ring of FIG. 3A;

FIG. 3C is a transverse cross-sectional view of the annuloplasty ring ofFIG. 3A;

FIG. 4A is a top view of an annuloplasty ring having a substantiallycircular configuration according to certain embodiments of theinvention;

FIG. 4B is a side view of the annuloplasty ring of FIG. 4A;

FIG. 4C is a transverse cross-sectional view of the annuloplasty ring ofFIG. 4A;

FIG. 5 is a top view of an annuloplasty ring having a substantiallyD-shaped configuration according to certain embodiments of theinvention;

FIG. 6A is a schematic diagram of a top view of a shape memory wirehaving a substantially D-shaped configuration according to certainembodiments of the invention;

FIGS. 6B-6E are schematic diagrams of side views of the shape memorywire of FIG. 6A according to certain embodiments of the invention;

FIG. 7A is a perspective view in partial section of an annuloplasty ringcomprising the shape memory wire of FIG. 6A according to certainembodiments of the invention;

FIG. 7B is a perspective view in partial section of a portion of theannuloplasty ring of FIG. 7A;

FIG. 8 is a schematic diagram of a shape memory wire having asubstantially C-shaped configuration according to certain embodiments ofthe invention;

FIG. 9A is a perspective view in partial section of an annuloplasty ringcomprising the shape memory wire of FIG. 8 according to certainembodiments of the invention;

FIG. 9B is a perspective view in partial section of a portion of theannuloplasty ring of FIG. 9A;

FIG. 10A is a perspective view in partial section an annuloplasty ringcomprising a first shape memory wire and a second shape memory wireaccording to certain embodiments of the invention;

FIG. 10B is a top cross-sectional view of the annuloplasty ring of FIG.10A;

FIG. 11A is a perspective view in partial section of an annuloplastyring comprising a first shape memory wire and a second shape memory wireaccording to certain embodiments of the invention;

FIG. 11B is a top cross-sectional view of the annuloplasty ring of FIG.11A;

FIG. 12 is a perspective view of a shape memory wire wrapped in a coilaccording to certain embodiments of the invention;

FIGS. 13A and 13B are schematic diagrams illustrating an annuloplastyring according to certain embodiments of the invention;

FIG. 14 is a schematic diagram illustrating an annuloplasty ringaccording to certain embodiments of the invention;

FIG. 15 is a schematic diagram illustrating an annuloplasty ringaccording to certain embodiments of the invention;

FIGS. 16A and 16B are schematic diagrams illustrating an annuloplastyring having a plurality of temperature response zones or sectionsaccording to certain embodiments of the invention;

FIGS. 17A and 17B are schematic diagrams illustrating an annuloplastyring having a plurality of temperature response zones or sectionsaccording to certain embodiments of the invention;

FIG. 18 is a sectional view of a mitral valve with respect to anexemplary annuloplasty ring according to certain embodiments of theinvention;

FIG. 19 is a schematic diagram of a substantially C-shaped wirecomprising a shape memory material configured to contract in a firstdirection and expand in a second direction according to certainembodiments of the invention;

FIGS. 20A and 20B are schematic diagrams of a body member usable by anannuloplasty ring according to certain embodiments of the invention;

FIGS. 21A and 21B are schematic diagrams of a body member usable by anannuloplasty ring according to certain embodiments of the invention;

FIGS. 22A and 22B are schematic diagrams of a body member usable by anannuloplasty ring according to certain embodiments of the invention;

FIG. 23 is a transverse cross-sectional view of the body member of FIGS.21A and 21B;

FIG. 24 is a perspective view of a body member usable by an annuloplastyring according to certain embodiments comprising a first shape memoryband and a second shape memory band;

FIG. 25A is a schematic diagram illustrating the body member of FIG. 24in a first configuration or shape according to certain embodiments ofthe invention;

FIG. 25B is a schematic diagram illustrating the body member of FIG. 24in a second configuration or shape according to certain embodiments ofthe invention;

FIG. 25C is a schematic diagram illustrating the body member of FIG. 24in a third configuration or shape according to certain embodiments ofthe invention;

FIG. 26 is a perspective view illustrating an annuloplasty ringcomprising one or more thermal conductors according to certainembodiments of the invention;

FIGS. 27A-27C are transverse cross-sectional views of the annuloplastyring of FIG. 26 schematically illustrating exemplary embodiments of theinvention for conducting thermal energy to an internal shape memorywire; and

FIG. 28 is a schematic diagram of an annuloplasty ring comprising one ormore thermal conductors according to certain embodiments of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention involves systems and methods for reinforcingdysfunctional heart valves and other body structures with adjustablerings. In certain embodiments, an adjustable annuloplasty ring isimplanted into the body of a patient such as a human or other animal.The adjustable annuloplasty ring is implanted through an incision orbody opening either thoracically (e.g., open-heart surgery) orpercutaneously (e.g., via a femoral artery or vein, or other arteries orveins) as is known to someone skilled in the art. The adjustableannuloplasty ring is attached to the annulus of a heart valve to improveleaflet coaptation and to reduce regurgitation. The annuloplasty ringmay be selected from one or more shapes comprising a round or circularshape, an oval shape, a C-shape, a D-shape, a U-shape, an open circleshape, an open oval shape, and other curvilinear shapes.

The size of the annuloplasty ring can be adjusted postoperatively tocompensate for changes in the size of the heart. As used herein,“postoperatively” refers to a time after implanting the adjustableannuloplasty ring and closing the body opening through which theadjustable annuloplasty ring was introduced into the patient's body. Forexample, the annuloplasty ring may be implanted in a child whose heartgrows as the child gets older. Thus, the size of the annuloplasty ringmay need to be increased. As another example, the size of an enlargedheart may start to return to its normal size after an annuloplasty ringis implanted. Thus, the size of the annuloplasty ring may need to bedecreased postoperatively to continue to reinforce the heart valveannulus.

In certain embodiments, the annuloplasty ring comprises a shape memorymaterial that is responsive to changes in temperature and/or exposure toa magnetic field. Shape memory is the ability of a material to regainits shape after deformation. Shape memory materials include polymers,metals, metal alloys and ferromagnetic alloys. The annuloplasty ring isadjusted in vivo by applying an energy source to activate the shapememory material and cause it to change to a memorized shape. The energysource may include, for example, radio frequency (RF) energy, x-rayenergy, microwave energy, ultrasonic energy such as focused ultrasound,high intensity focused ultrasound (HIFU) energy, light energy, electricfield energy, magnetic field energy, combinations of the foregoing, orthe like. For example, one embodiment of electromagnetic radiation thatis useful is infrared energy having a wavelength in a range betweenapproximately 750 nanometers and approximately 1600 nanometers. Thistype of infrared radiation may be produced efficiently by a solid statediode laser. In certain embodiments, the annuloplasty ring implant isselectively heated using short pulses of energy having an on and offperiod between each cycle. The energy pulses provide segmental heatingwhich allows segmental adjustment of portions of the annuloplasty ringwithout adjusting the entire implant.

In certain embodiments, the annuloplasty ring includes an energyabsorbing material to increase heating efficiency and localize heatingin the area of the shape memory material. Thus, damage to thesurrounding tissue is reduced or minimized. Energy absorbing materialsfor light or laser activation energy may include nanoshells, nanospheresand the like, particularly where infrared laser energy is used toenergize the material. Such nanoparticles may be made from a dielectric,such as silica, coated with an ultra thin layer of a conductor, such asgold, and be selectively tuned to absorb a particular frequency ofelectromagnetic radiation. In certain such embodiments, thenanoparticles range in size between about 5 nanometers and about 20nanometers and can be suspended in a suitable material or solution, suchas saline solution. Coatings comprising nanotubes or nanoparticles canalso be used to absorb energy from, for example, HIFU, MRI, inductiveheating, or the like.

In other embodiments, thin film deposition or other coating techniquessuch as sputtering, reactive sputtering, metal ion implantation,physical vapor deposition, and chemical deposition can be used to coverportions or all of the annuloplasty ring. Such coatings can be eithersolid or microporous. When HIFU energy is used, for example, amicroporous structure traps and directs the HIFU energy toward the shapememory material. The coating improves thermal conduction and heatremoval. In certain embodiments, the coating also enhances radio-opacityof the annuloplasty ring implant. Coating materials can be selected fromvarious groups of biocompatible organic or non-organic, metallic ornon-metallic materials such as Titanium Nitride (TiN), Iridium Oxide(Irox), Carbon, Platinum black, Titanium Carbide (TiC) and othermaterials used for pacemaker electrodes or implantable pacemaker leads.Other materials discussed herein or known in the art can also be used toabsorb energy.

In addition, or in other embodiments, fine conductive wires such asplatinum coated copper, titanium, tantalum, stainless steel, gold, orthe like, are wrapped around the shape memory material to allow focusedand rapid heating of the shape memory material while reducing undesiredheating of surrounding tissues.

In certain embodiments, the energy source is applied surgically eitherduring implantation or at a later time. For example, the shape memorymaterial can be heated during implantation of the annuloplasty ring bytouching the annuloplasty ring with warm object. As another example, theenergy source can be surgically applied after the annuloplasty ring hasbeen implanted by percutaneously inserting a catheter into the patient'sbody and applying the energy through the catheter. For example, RFenergy, light energy or thermal energy (e.g., from a heating elementusing resistance heating) can be transferred to the shape memorymaterial through a catheter positioned on or near the shape memorymaterial. Alternatively, thermal energy can be provided to the shapememory material by injecting a heated fluid through a catheter orcirculating the heated fluid in a balloon through the catheter placed inclose proximity to the shape memory material. As another example, theshape memory material can be coated with a photodynamic absorbingmaterial which is activated to heat the shape memory material whenilluminated by light from a laser diode or directed to the coatingthrough fiber optic elements in a catheter. In certain such embodiments,the photodynamic absorbing material includes one or more drugs that arereleased when illuminated by the laser light.

In certain embodiments, a removable subcutaneous electrode or coilcouples energy from a dedicated activation unit. In certain suchembodiments, the removable subcutaneous electrode provides telemetry andpower transmission between the system and the annuloplasty ring. Thesubcutaneous removable electrode allows more efficient coupling ofenergy to the implant with minimum or reduced power loss. In certainembodiments, the subcutaneous energy is delivered via inductivecoupling.

In other embodiments, the energy source is applied in a non-invasivemanner from outside the patient's body. In certain such embodiments, theexternal energy source is focused to provide directional heating to theshape memory material so as to reduce or minimize damage to thesurrounding tissue. For example, in certain embodiments, a handheld orportable device comprising an electrically conductive coil generates anelectromagnetic field that non-invasively penetrates the patient's bodyand induces a current in the annuloplasty ring. The current heats theannuloplasty ring and causes the shape memory material to transform to amemorized shape. In certain such embodiments, the annuloplasty ring alsocomprises an electrically conductive coil wrapped around or embedded inthe memory shape material. The externally generated electromagneticfield induces a current in the annuloplasty ring's coil, causing it toheat and transfer thermal energy to the shape memory material.

In certain other embodiments, an external HIFU transducer focusesultrasound energy onto the implanted annuloplasty ring to heat the shapememory material. In certain such embodiments, the external HIFUtransducer is a handheld or portable device. The terms “HIFU,” “highintensity focused ultrasound” or “focused ultrasound” as used herein arebroad terms and are used at least in their ordinary sense and include,without limitation, acoustic energy within a wide range of intensitiesand/or frequencies. For example, HIFU includes acoustic energy focusedin a region, or focal zone, having an intensity and/or frequency that isconsiderably less than what is currently used for ablation in medicalprocedures. Thus, in certain such embodiments, the focused ultrasound isnot destructive to the patient's cardiac tissue. In certain embodiments,HIFU includes acoustic energy within a frequency range of approximately0.5 MHz and approximately 30 MHz and a power density within a range ofapproximately 1 W/cm² and approximately 500 W/cm².

In certain embodiments, the annuloplasty ring comprises an ultrasoundabsorbing material or hydro-gel material that allows focused and rapidheating when exposed to the ultrasound energy and transfers thermalenergy to the shape memory material. In certain embodiments, a HIFUprobe is used with an adaptive lens to compensate for heart andrespiration movement. The adaptive lens has multiple focal pointadjustments. In certain embodiments, a HIFU probe with adaptivecapabilities comprises a phased array or linear configuration. Incertain embodiments, an external HIFU probe comprises a lens configuredto be placed between a patient's ribs to improve acoustic windowpenetration and reduce or minimize issues and challenges regardingpassing through bones. In certain embodiments, HIFU energy issynchronized with an ultrasound imaging device to allow visualization ofthe annuloplasty ring implant during HIFU activation. In addition, or inother embodiments, ultrasound imaging is used to non-invasively monitorthe temperature of tissue surrounding the annuloplasty ring by usingprinciples of speed of sound shift and changes to tissue thermalexpansion.

In certain embodiments, non-invasive energy is applied to the implantedannuloplasty ring using a Magnetic Resonance Imaging (MRI) device. Incertain such embodiments, the shape memory material is activated by aconstant magnetic field generated by the MRI device. In addition, or inother embodiments, the MRI device generates RF pulses that inducecurrent in the annuloplasty ring and heat the shape memory material. Theannuloplasty ring can include one or more coils and/or MRI energyabsorbing material to increase the efficiency and directionality of theheating. Suitable energy absorbing materials for magnetic activationenergy include particulates of ferromagnetic material. Suitable energyabsorbing materials for RF energy include ferrite materials as well asother materials configured to absorb RF energy at resonant frequenciesthereof.

In certain embodiments, the MRI device is used to determine the size ofthe implanted annuloplasty ring before, during and/or after the shapememory material is activated. In certain such embodiments, the MRIdevice generates RF pulses at a first frequency to heat the shape memorymaterial and at a second frequency to image the implanted annuloplastyring. Thus, the size of the annuloplasty ring can be measured withoutheating the ring. In certain such embodiments, an MRI energy absorbingmaterial heats sufficiently to activate the shape memory material whenexposed to the first frequency and does not substantially heat whenexposed to the second frequency. Other imaging techniques known in theart can also be used to determine the size of the implanted ringincluding, for example, ultrasound imaging, computed tomography (CT)scanning, X-ray imaging, or the like. In certain embodiments, suchimaging techniques also provide sufficient energy to activate the shapememory material.

In certain embodiments, imaging and resizing of the annuloplasty ring isperformed as a separate procedure at some point after the annuloplastyring as been surgically implanted into the patient's heart and thepatient's heart, pericardium and chest have been surgically closed.However, in certain other embodiments, it is advantageous to perform theimaging after the heart and/or pericardium have been closed, but beforeclosing the patient's chest, to check for leakage or the amount ofregurgitation. If the amount of regurgitation remains excessive afterthe annuloplasty ring has been implanted, energy from the imaging device(or from another source as discussed herein) can be applied to the shapememory material so as to at least partially contract the annuloplastyring and reduce regurgitation to an acceptable level. Thus, the successof the surgery can be checked and corrections can be made, if necessary,before closing the patient's chest.

In certain embodiments, activation of the shape memory material issynchronized with the heart beat during an imaging procedure. Forexample, an imaging technique can be used to focus HIFU energy onto anannuloplasty ring in a patient's body during a portion of the cardiaccycle. As the heart beats, the annuloplasty ring may move in and out ofthis area of focused energy. To reduce damage to the surrounding tissue,the patient's body is exposed to the HIFU energy only during portions ofthe cardiac cycle that focus the HIFU energy onto the cardiac ring. Incertain embodiments, the energy is gated with a signal that representsthe cardiac cycle such as an electrocardiogram signal. In certain suchembodiments, the synchronization and gating is configured to allowdelivery of energy to the shape memory materials at specific timesduring the cardiac cycle to avoid or reduce the likelihood of causingarrhythmia or fibrillation during vulnerable periods. For example, theenergy can be gated so as to only expose the patient's heart to theenergy during the T wave of the electrocardiogram signal.

As discussed above, shape memory materials include, for example,polymers, metals, and metal alloys including ferromagnetic alloys.Exemplary shape memory polymers that are usable for certain embodimentsof the present invention are disclosed by Langer, et al. in U.S. Pat.No. 6,720,402, issued Apr. 13, 2004, U.S. Pat. No. 6,388,043, issued May14, 2002, and U.S. Pat. No. 6,160,084, issued Dec. 12, 2000, each ofwhich are hereby incorporated by reference herein. Shape memory polymersrespond to changes in temperature by changing to one or more permanentor memorized shapes. In certain embodiments, the shape memory polymer isheated to a temperature between approximately 38 degrees Celsius andapproximately 60 degrees Celsius. In certain other embodiments, theshape memory polymer is heated to a temperature in a range betweenapproximately 40 degrees Celsius and approximately 55 degrees Celsius.In certain embodiments, the shape memory polymer has a two-way shapememory effect wherein the shape memory polymer is heated to change it toa first memorized shape and cooled to change it to a second memorizedshape. The shape memory polymer can be cooled, for example, by insertingor circulating a cooled fluid through a catheter.

Shape memory polymers implanted in a patient's body can be heatednon-invasively using, for example, external light energy sources such asinfrared, near-infrared, ultraviolet, microwave and/or visible lightsources. Preferably, the light energy is selected to increase absorptionby the shape memory polymer and reduce absorption by the surroundingtissue. Thus, damage to the tissue surrounding the shape memory polymeris reduced when the shape memory polymer is heated to change its shape.In other embodiments, the shape memory polymer comprises gas bubbles orbubble containing liquids such as fluorocarbons and is heated byinducing a cavitation effect in the gas/liquid when exposed to HIFUenergy. In other embodiments, the shape memory polymer may be heatedusing electromagnetic fields and may be coated with a material thatabsorbs electromagnetic fields.

Certain metal alloys have shape memory qualities and respond to changesin temperature and/or exposure to magnetic fields. Exemplary shapememory alloys that respond to changes in temperature includetitanium-nickel, copper-zinc-aluminum, copper-aluminum-nickel,iron-manganese-silicon, iron-nickel-aluminum, gold-cadmium, combinationsof the foregoing, and the like. In certain embodiments, the shape memoryalloy comprises a biocompatible material such as a titanium-nickelalloy.

Shape memory alloys exist in two distinct solid phases called martensiteand austenite. The martensite phase is relatively soft and easilydeformed, whereas the austenite phase is relatively stronger and lesseasily deformed. For example, shape memory alloys enter the austenitephase at a relatively high temperature and the martensite phase at arelatively low temperature. Shape memory alloys begin transforming tothe martensite phase at a start temperature (M_(s)) and finishtransforming to the martensite phase at a finish temperature (M_(f)).Similarly, such shape memory alloys begin transforming to the austenitephase at a start temperature (A_(s)) and finish transforming to theaustenite phase at a finish temperature (A_(f)). Both transformationshave a hysteresis. Thus, the M_(s) temperature and the A_(f) temperatureare not coincident with each other, and the M_(f) temperature and theA_(s) temperature are not coincident with each other.

In certain embodiments, the shape memory alloy is processed to form amemorized shape in the austenite phase in the form of a ring or partialring. The shape memory alloy is then cooled below the M_(f) temperatureto enter the martensite phase and deformed into a larger or smallerring. For example, in certain embodiments, the shape memory alloy isformed into a ring or partial ring that is larger than the memorizedshape but still small enough to improve leaflet coaptation and reduceregurgitation in a heart valve upon being attached to the heart valveannulus. In certain such embodiments, the shape memory alloy issufficiently malleable in the martensite phase to allow a user such as aphysician to adjust the circumference of the ring in the martensitephase by hand to achieve a desired fit for a particular heart valveannulus. After the ring is attached to the heart valve annulus, thecircumference of the ring can be adjusted non-invasively by heating theshape memory alloy to an activation temperature (e.g., temperaturesranging from the A_(s) temperature to the A_(f) temperature).

Thereafter, when the shape memory alloy is exposed to a temperatureelevation and transformed to the austenite phase, the alloy changes inshape from the deformed shape to the memorized shape. Activationtemperatures at which the shape memory alloy causes the shape of theannuloplasty ring to change shape can be selected and built into theannuloplasty ring such that collateral damage is reduced or eliminatedin tissue adjacent the annuloplasty ring during the activation process.Exemplary A_(f) temperatures for suitable shape memory alloys rangebetween approximately 45 degrees Celsius and approximately 70 degreesCelsius. Furthermore, exemplary M_(s) temperatures range betweenapproximately 10 degrees Celsius and approximately 20 degrees Celsius,and exemplary M_(f) temperatures range between approximately −1 degreesCelsius and approximately 15 degrees Celsius. The size of theannuloplasty ring can be changed all at once or incrementally in smallsteps at different times in order to achieve the adjustment necessary toproduce the desired clinical result.

Certain shape memory alloys may further include a rhombohedral phase,having a rhombohedral start temperature (R_(s)) and a rhombohedralfinish temperature (R_(f)), that exists between the austenite andmartensite phases. An example of such a shape memory alloy is a NiTialloy, which is commercially available from Memry Corporation (Bethel,Conn.). In certain embodiments, an exemplary R_(s) temperature range isbetween approximately 30 degrees Celsius and approximately 50 degreesCelsius, and an exemplary R_(f) temperature range is betweenapproximately 20 degrees Celsius and approximately 35 degrees Celsius.One benefit of using a shape memory material having a rhombohedral phaseis that in the rhomobohedral phase the shape memory material mayexperience a partial physical distortion, as compared to the generallyrigid structure of the austenite phase and the generally deformablestructure of the martensite phase.

Certain shape memory alloys exhibit a ferromagnetic shape memory effectwherein the shape memory alloy transforms from the martensite phase tothe austenite phase when exposed to an external magnetic field. The term“ferromagnetic” as used herein is a broad term and is used in itsordinary sense and includes, without limitation, any material thateasily magnetizes, such as a material having atoms that orient theirelectron spins to conform to an external magnetic field. Ferromagneticmaterials include permanent magnets, which can be magnetized through avariety of modes, and materials, such as metals, that are attracted topermanent magnets. Ferromagnetic materials also include electromagneticmaterials that are capable of being activated by an electromagnetictransmitter, such as one located outside the heart 100. Furthermore,ferromagnetic materials may include one or more polymer-bonded magnets,wherein magnetic particles are bound within a polymer matrix, such as abiocompatible polymer. The magnetic materials can comprise isotropicand/or anisotropic materials, such as for example NdFeB (Neodynium IronBoron), SmCo (Samarium Cobalt), ferrite and/or AlNiCo (Aluminum NickelCobalt) particles.

Thus, an annuloplasty ring comprising a ferromagnetic shape memory alloycan be implanted in a first configuration having a first shape and laterchanged to a second configuration having a second (e.g., memorized)shape without heating the shape memory material above the A_(s)temperature. Advantageously, nearby healthy tissue is not exposed tohigh temperatures that could damage the tissue. Further, since theferromagnetic shape memory alloy does not need to be heated, the size ofthe annuloplasty ring can be adjusted more quickly and more uniformlythan by heat activation.

Exemplary ferromagnetic shape memory alloys include Fe—C, Fe—Pd,Fe—Mn—Si, Co—Mn, Fe—Co—Ni—Ti, Ni—Mn—Ga, Ni₂MnGa, Co—Ni—Al, and the like.Certain of these shape memory materials may also change shape inresponse to changes in temperature. Thus, the shape of such materialscan be adjusted by exposure to a magnetic field, by changing thetemperature of the material, or both.

In certain embodiments, combinations of different shape memory materialsare used. For example, annuloplasty rings according to certainembodiments comprise a combination of shape memory polymer and shapememory alloy (e.g., NiTi). In certain such embodiments, an annuloplastyring comprises a shape memory polymer tube and a shape memory alloy(e.g., NiTi) disposed within the tube. Such embodiments are flexible andallow the size and shape of the shape memory to be further reducedwithout impacting fatigue properties. In addition, or in otherembodiments, shape memory polymers are used with shape memory alloys tocreate a bi-directional (e.g., capable of expanding and contracting)annuloplasty ring. Bi-directional annuloplasty rings can be created witha wide variety of shape memory material combinations having differentcharacteristics.

In the following description, reference is made to the accompanyingdrawings, which form a part hereof, and which show, by way ofillustration, specific embodiments or processes in which the inventionmay be practiced. Where possible, the same reference numbers are usedthroughout the drawings to refer to the same or like components. In someinstances, numerous specific details are set forth in order to provide athorough understanding of the present disclosure. The presentdisclosure, however, may be practiced without the specific details orwith certain alternative equivalent components and methods to thosedescribed herein. In other instances, well-known components and methodshave not been described in detail so as not to unnecessarily obscureaspects of the present disclosure.

FIGS. 1A-1C illustrate an adjustable annuloplasty ring 100 according tocertain embodiments that can be adjusted in vivo after implantation intoa patient's body. The annuloplasty ring 100 has a substantially annularconfiguration and comprises a tubular body member 112 that folds backupon itself in a substantial circle having a nominal diameter asindicated by arrow 123. The tubular body member 112 comprises areceptacle end 114 and an insert end 116. The insert end 116 of thetubular member 112 is reduced in outer diameter or transverse dimensionas compared to the receptacle end 114. As used herein, “dimension” is abroad term having its ordinary and customary meaning and includes a sizeor distance from a first point to a second point along a line or arc.For example, a dimension may be a circumference, diameter, radius, arclength, or the like. As another example, a dimension may be a distancebetween an anterior portion and a posterior portion of an annulus.

The receptacle end accepts the insert end 116 of the tubular member 112to complete the ring-like structure of the annuloplasty ring 100. Theinsert end 116 slides freely within the receptacle end 114 of theannuloplasty ring 100 which allows contraction of the overallcircumference of the ring 100 as the insert end 116 enters thereceptacle end 114 as shown by arrows 118 in FIG. 1A. In certainembodiments, the nominal diameter or transverse dimension 123 of theannuloplasty ring 100 can be adjusted from approximately 25 mm toapproximately 38 mm. However, an artisan will recognize from thedisclosure herein that the diameter or transverse dimension 123 of theannuloplasty ring 100 can be adjusted to other sizes depending on theparticular application. Indeed, the diameter or transverse dimension 123of the annuloplasty ring 100 can be configured to reinforce bodystructures substantially smaller than 25 mm and substantially largerthan 38 mm.

An artisan will recognize from the disclosure herein that in otherembodiments the insert end 116 can couple with the receptacle end 114without being inserted in the receptacle end 114. For example, theinsert end 116 can overlap the receptacle end 114 such that it slidesadjacent thereto. In other embodiments, for example, the ends 114, 116may grooved to guide the movement of the adjacent ends 114, 116 relativeto one another. Other embodiments within the scope of the invention willoccur to those skilled in the art.

The annuloplasty ring 100 also comprises a suturable material 128, shownpartially cut away in FIG. 1A, and not shown in FIGS. 1B and 1C forclarity. The suturable material 128 is disposed about the tubular member112 to facilitate surgical implantation of the annuloplasty ring 100 ina body structure, such as about a heart valve annulus. In certainembodiments, the suturable material 128 comprises a suitablebiocompatible material such as Dacron®, woven velour, polyurethane,polytetrafluoroethylene (PTFE), heparin-coated fabric, or the like. Inother embodiments, the suturable material 128 comprises a biologicalmaterial such as bovine or equine pericardium, homograft, patient graft,or cell-seeded tissue. The suturable material 128 may be disposed aboutthe entire circumference of the tubular member 112, or selected portionsthereof. For example, in certain embodiments, the suturable material 128is disposed so as to enclose substantially the entire tubular member 112except at the narrowed insert end 116 that slides into the receptacleend 118 of the tubular member 112.

As shown in FIGS. 1A and 1B, in certain embodiments, the annuloplastyring 100 also comprises a ratchet member 120 secured to the receptacleend 114 of the tubular member 112. The ratchet member 120 comprises apawl 122 configured to engage transverse slots 124 (shown in FIG. 1B) onthe insert end 116 of the tubular member 112. The pawl 122 of theratchet member 120 engages the slots 124 in such a way as to allowcontraction of the circumference of the annuloplasty ring 100 andprevent or reduce circumferential expansion of the annuloplasty ring100. Thus, the ratchet reduces unwanted circumferential expansion of theannuloplasty ring 100 after implantation due, for example, to dynamicforces on the annuloplasty ring 100 from the heart tissue duringsystolic contraction of the heart.

In certain embodiments, the tubular member 112 comprises a rigidmaterial such as stainless steel, titanium, or the like, or a flexiblematerial such as silicon rubber, Dacron®, or the like. In certain suchembodiments, after implantation into a patient's body, the circumferenceof the annuloplasty ring 100 is adjusted in vivo by inserting a catheter(not shown) into the body and pulling a wire (not shown) attached to thetubular member 112 through the catheter to manually slide the insert end116 of the tubular member 112 into the receptacle end 114 of the tubularmember 112. As the insert end 116 slides into the receptacle end 114,the pawl 122 of the ratchet member 120 engages the slots 124 on theinsert end 116 to hold the insert end 116 in the receptacle end 114.Thus, for example, as the size of a heart valve annulus reduces afterimplantation of the annuloplasty ring 100, the size of the annuloplastyring 100 can also be reduced to provide an appropriate amount ofreinforcement to the heart valve.

In certain other embodiments, the tubular member 112 comprises a shapememory material that is responsive to changes in temperature and/orexposure to a magnetic field. As discussed above, the shape memorymaterial may include shape memory polymers (e.g., polylactic acid (PLA),polyglycolic acid (PGA)) and/or shape memory alloys (e.g.,nickel-titanium) including ferromagnetic shape memory alloys (e.g.,Fe—C, Fe—Pd, Fe—Mn—Si, Co—Mn, Fe—Co—Ni—Ti, Ni—Mn—Ga, Ni₂MnGa, Co—Ni—Al).In certain such embodiments, the annuloplasty ring 100 is adjusted invivo by applying an energy source such as radio frequency energy, X-rayenergy, microwave energy, ultrasonic energy such as high intensityfocused ultrasound (HIFU) energy, light energy, electric field energy,magnetic field energy, combinations of the foregoing, or the like.Preferably, the energy source is applied in a non-invasive manner fromoutside the body. For example, as discussed above, a magnetic fieldand/or RF pulses can be applied to the annuloplasty ring 100 within apatient's body with an apparatus external to the patient's body such asis commonly used for magnetic resonance imaging (MRI). However, in otherembodiments, the energy source may be applied surgically such as byinserting a catheter into the body and applying the energy through thecatheter.

In certain embodiments, the tubular body member 112 comprises a shapememory material that responds to the application of temperature thatdiffers from a nominal ambient temperature, such as the nominal bodytemperature of 37 degrees Celsius for humans. The tubular member 112 isconfigured to respond by starting to contract upon heating the tubularmember 112 above the A_(s) temperature of the shape memory material. Incertain such embodiments, the annuloplasty ring 100 has an initialdiameter or transverse dimension 123 of approximately 30 mm, andcontracts or shrinks to a transverse dimension 123 of approximately 23mm to approximately 28 mm, or any increment between those values. Thisproduces a contraction percentage in a range between approximately 6percent and approximately 23 percent, where the percentage ofcontraction is defined as a ratio of the difference between the startingdiameter and finish diameter divided by the starting diameter.

The activation temperatures (e.g., temperatures ranging from the A_(s)temperature to the A_(f) temperature) at which the tubular member 112contracts to a reduced circumference may be selected and built into theannuloplasty ring 100 such that collateral damage is reduced oreliminated in tissue adjacent the annuloplasty ring 100 during theactivation process. Exemplary A_(f) temperatures for the shape memorymaterial of the tubular member 112 at which substantially maximumcontraction occurs are in a range between approximately 38 degreesCelsius and approximately 1310 degrees Celsius. In certain embodiments,the A_(f) temperature is in a range between approximately 39 degreesCelsius and approximately 75 degrees Celsius. For some embodiments thatinclude shape memory polymers for the tubular member 112, activationtemperatures at which the glass transition of the material orsubstantially maximum contraction occur range between approximately 38degrees Celsius and approximately 60 degrees Celsius. In other suchembodiments, the activation temperature is in a range betweenapproximately 40 degrees Celsius and approximately 59 degrees Celsius.

In certain embodiments, the tubular member 112 is shape set in theaustenite phase to a remembered configuration during the manufacturingof the tubular member 112 such that the remembered configuration is thatof a relatively small circumferential value with the insert end 116fully inserted into the receptacle end 114. After cooling the tubularmember 112 below the M_(f) temperature, the tubular member 112 ismanually deformed to a larger circumferential value with the insert end116 only partially inserted into the receptacle end 114 to achieve adesired starting nominal circumference for the annuloplasty ring 100. Incertain such embodiments, the tubular member 112 is sufficientlymalleable in the martensite phase to allow a user such as a physician toadjust the circumferential value by hand to achieve a desired fit withthe heart valve annulus. In certain embodiments, the starting nominalcircumference for the annuloplasty ring 100 is configured to improveleaflet coaptation and reduce regurgitation in a heart valve.

After implantation, the annuloplasty ring 100 is preferably activatednon-invasively by the application of energy to the patient's body toheat the tubular member 112. In certain embodiments, an MRI device isused as discussed above to heat the tubular member 112, which thencauses the shape memory material of the tubular member 112 to transformto the austenite phase and remember its contracted configuration. Thus,the circumference of the annuloplasty ring 100 is reduced in vivowithout the need for surgical intervention. Standard techniques forfocusing the magnetic field from the MRI device onto the annuloplastyring 100 may be used. For example, a conductive coil can be wrappedaround the patient in an area corresponding to the annuloplasty ring100. In other embodiments, the shape memory material is activated byexposing it other sources of energy, as discussed above.

The circumference reduction process, either non-invasively or through acatheter, can be carried out all at once or incrementally in small stepsat different times in order to achieve the adjustment necessary toproduce the desired clinical result. If heating energy is applied suchthat the temperature of the tubular member 112 does not reach the A_(f)temperature for substantially maximum transition contraction, partialshape memory transformation and contraction may occur. FIG. 2graphically illustrates the relationship between the temperature of thetubular member 112 and the diameter or transverse dimension 123 of theannuloplasty ring 100 according to certain embodiments. At bodytemperature of approximately 37 degrees Celsius, the diameter of thetubular member 112 has a first diameter d₀. The shape memory material isthen increased to a first raised temperature T₁. In response, thediameter of the tubular member 112 reduces to a second diameter d_(n).The diameter of the tubular member 112 can then be reduced to a thirddiameter d_(nm) by raising the temperature to a second temperature T₂.

As graphically illustrated in FIG. 2, in certain embodiments, the changein diameter from d₀ to d_(nm) is substantially continuous as thetemperature is increased from body temperature to T₂. For example, incertain embodiments a magnetic field of about 2.5 Tesla to about 3.0Tesla is used to raise the temperature of the tubular member 112 abovethe A_(f) temperature to complete the austenite phase and return thetubular member 112 to the remembered configuration with the insert end116 fully inserted into the receptacle end 114. However, a lowermagnetic field (e.g., 0.5 Tesla) can initially be applied and increased(e.g., in 0.5 Tesla increments) until the desired level of heating anddesired contraction of the annuloplasty ring 100 is achieved. In otherembodiments, the tubular member 112 comprises a plurality of shapememory materials with different activation temperatures and the diameterof the tubular member 112 is reduced in steps as the temperatureincreases.

Whether the shape change is continuous or stepped, the diameter ortransverse dimension 123 of the ring 100 can be assessed or monitoredduring the contraction process to determine the amount of contraction byuse of MRI imaging, ultrasound imaging, computed tomography (CT), X-rayor the like. If magnetic energy is being used to activate contraction ofthe ring 100, for example, MRI imaging techniques can be used thatproduce a field strength that is lower than that required for activationof the annuloplasty ring 100.

In certain embodiments, the tubular member 112 comprises an energyabsorption enhancement material 126. As shown in FIGS. 1A and 1C, theenergy absorption enhancement material 126 may be disposed within aninner chamber of the tubular member 112. As shown in FIG. 1C (and notshown in FIG. 1A for clarity), the energy absorption enhancementmaterial 126 may also be coated on the outside of the tubular member 112to enhance energy absorption by the tubular member 112. For embodimentsthat use energy absorption enhancement material 126 for enhancedabsorption, it may be desirable for the energy absorption enhancementmaterial 126, a carrier material (not shown) surrounding the energyabsorption enhancement material 126, if there is one, or both to bethermally conductive. Thus, thermal energy from the energy absorptionenhancement material 126 is efficiently transferred to the shape memorymaterial of the annuloplasty ring 100, such as the tubular member 112.

As discussed above, the energy absorption enhancement material 126 mayinclude a material or compound that selectively absorbs a desiredheating energy and efficiently converts the non-invasive heating energyto heat which is then transferred by thermal conduction to the tubularmember 112. The energy absorption enhancement material 126 allows thetubular member 112 to be actuated and adjusted by the non-invasiveapplication of lower levels of energy and also allows for the use ofnon-conducting materials, such as shape memory polymers, for the tubularmember 112. For some embodiments, magnetic flux ranging between about2.5 Tesla and about 3.0 Tesla may be used for activation. By allowingthe use of lower energy levels, the energy absorption enhancementmaterial 126 also reduces thermal damage to nearby tissue. Suitableenergy absorption enhancement materials 126 are discussed above.

In certain embodiments, a circumferential contraction cycle can bereversed to induce an expansion of the annuloplasty ring 100. Some shapememory alloys, such as NiTi or the like, respond to the application of atemperature below the nominal ambient temperature. After acircumferential contraction cycle has been performed, the tubular member112 is cooled below the M_(s) temperature to start expanding theannuloplasty ring 100. The tubular member 112 can also be cooled belowthe M_(f) temperature to finish the transformation to the martensitephase and reverse the contraction cycle. As discussed above, certainpolymers also exhibit a two-way shape memory effect and can be used toboth expand and contract the annuloplasty ring 100 through heating andcooling processes. Cooling can be achieved, for example, by inserting acool liquid onto or into the annuloplasty ring 100 through a catheter,or by cycling a cool liquid or gas through a catheter placed near theannuloplasty ring 100. Exemplary temperatures for a NiTi embodiment forcooling and reversing a contraction cycle range between approximately 20degrees Celsius and approximately 30 degrees Celsius.

In certain embodiments, external stresses are applied to the tubularmember 112 during cooling to expand the annuloplasty ring 100. Incertain such embodiments, one or more biasing elements (not shown) areoperatively coupled to the tubular member 112 so as to exert acircumferentially expanding force thereon. For example, in certainembodiments a biasing element such as a spring (not shown) is disposedin the receptacle end 114 of the tubular member 112 so as to push theinsert end 16 at least partially out of the receptacle end 114 duringcooling. In such embodiments, the tubular member 112 does not includethe ratchet member 120 such that the insert end 116 can slide freelyinto or out of the receptacle end 114.

In certain embodiments, the tubular member comprises ferromagnetic shapememory material, as discussed above. In such embodiments, the diameterof the tubular member 112 can be changed by exposing the tubular member112 to a magnetic field. Advantageously, nearby healthy tissue is notexposed to high temperatures that could damage the tissue. Further,since the shape memory material does not need to be heated, the size ofthe tubular member 112 can be adjusted more quickly and more uniformlythan by heat activation.

FIGS. 3A-3C illustrate an embodiment of an adjustable annuloplasty ring300 that is similar to the annuloplasty ring 100 discussed above, buthaving a D-shaped configuration instead of a circular configuration. Theannuloplasty ring 300 comprises a tubular body member 311 having areceptacle end 312 and an insert end 314 sized and configured to slidefreely in the hollow receptacle end 312 in an axial direction whichallows the annuloplasty ring 300 to constrict upon activation to alesser circumference or transverse dimension as indicated by arrows 316.The annuloplasty ring 300 has a major transverse dimension indicated byarrow 318 that is reduced upon activation of the annuloplasty ring 300.The major transverse dimension indicated by arrow 318 can be the same asor similar to the transverse dimension indicated by arrow 123 discussedabove. In certain embodiments, the features, dimensions and materials ofthe annuloplasty ring 300 are the same as or similar to the features,dimensions and materials of annuloplasty ring 100 discussed above. TheD-shaped configuration of ring 32 allows a proper fit of the ring 32with the morphology of some particular heart valves.

FIGS. 4A-4C show an embodiment of an annuloplasty ring 400 that includesa continuous tubular member 410 surrounded by a suturable material 128.The tubular member 410 has a substantially circular transverse crosssection, as shown in FIG. 4C, and has an absorption enhancing material126 disposed within an inner chamber of the tubular member 410. Incertain embodiments, the absorption enhancing material 126 is alsodisposed on the outer surface of the tubular member 410. The tubularmember 410 may be made from a shape memory material such as a shapememory polymer or a shape memory alloy including a ferromagnetic shapememory alloy, as discussed above.

For embodiments of the annuloplasty ring 400 with a tubular member 410made from a continuous piece of shape memory alloy (e.g., NiTi alloy) orshape memory polymer, the annuloplasty ring 400 can be activated by thesurgical and/or non-invasive application of heating energy by themethods discussed above with regard to other embodiments. Forembodiments of the annuloplasty ring 400 with a tubular member 410 madefrom a continuous piece of ferromagnetic shape memory alloy, theannuloplasty ring 400 can be activated by the non-invasive applicationof a suitable magnetic field. The annuloplasty ring 400 has a nominalinner diameter or transverse dimension indicated by arrow 412 in FIG. 4Athat is set during manufacture of the ring 400. In certain embodiments,the annuloplasty ring 400 is sufficiently malleable when it is implantedinto a patient's body that it can be adjusted by hand to be fitted to aparticular heart valve annulus.

In certain embodiments, upon activating the tubular member 410 by theapplication of energy, the tubular member 410 remembers and assumes aconfiguration wherein the transverse dimension is less than the nominaltransverse dimension 412. A contraction in a range between approximately6 percent to approximately 23 percent may be desirable in someembodiments which have continuous hoops of shape memory tubular members410. In certain embodiments, the tubular member 410 comprises a shapememory NiTi alloy having an inner transverse dimension in a rangebetween approximately 25 mm and approximately 38 mm. In certain suchembodiments, the tubular member 410 can contract or shrink in a rangebetween approximately 6 percent and approximately 23 percent, where thepercentage of contraction is defined as a ratio of the differencebetween the starting diameter and finish diameter divided by thestarting diameter. In certain embodiments, the annuloplasty ring 400 hasa nominal inner transverse dimension 412 of approximately 30 mm and aninner transverse dimension in a range between approximately 23 mm andapproximately 128 mm in a fully contracted state.

As discussed above in relation to FIG. 2, in certain embodiments, theinner transverse dimension 412 of certain embodiments can be altered asa function of the temperature of the tubular member 410. As alsodiscussed above, in certain such embodiments, the progress of the sizechange can be measured or monitored in real-time conventional imagingtechniques. Energy from conventional imaging devices can also be used toactivate the shape memory material and change the inner transversedimension 412 of the tubular member 410. In certain embodiments, thefeatures, dimensions and materials of the annuloplasty ring 400 are thesame as or similar to the features, dimensions and materials of theannuloplasty ring 100 discussed above. For example, in certainembodiments, the tubular member 410 comprises a shape memory materialthat exhibits a two-way shape memory effect when heated and cooled.Thus, the annuloplasty ring 400, in certain such embodiments, can becontracted and expanded.

FIG. 5 illustrates a top view of an annuloplasty ring 500 having aD-shaped configuration according to certain embodiments. Theannuloplasty ring 500 includes a continuous tubular member 510comprising a shape memory material that has a nominal inner transversedimension indicated by arrow 512 that may contract or shrink upon theactivation of the shape memory material by surgically or non-invasiveapplying energy thereto, as discussed above. The tubular member 510 maycomprise a homogeneous shape memory material, such as a shape memorypolymer or a shape memory alloy including, for example, a ferromagneticshape memory alloy.

Alternatively, the tubular member 510 may comprise two or more sectionsor zones of shape memory material having different temperature responsecurves. The shape memory response zones may be configured in order toachieve a desired configuration of the annuloplasty ring 500 as a wholewhen in a contracted state, either fully contracted or partiallycontracted. For example, the tubular member 510 may have a first zone orsection 514 that includes the arched portion of the tubular member thatterminates at or near the corners 516 and a second zone or section 518that includes the substantially straight portion of the tubular member510 disposed directly between the corners 516.

The annuloplasty ring 500 is shown in a contracted state in FIG. 5 asindicated by the dashed lines 520, 522, which represent contractedstates of certain embodiments wherein both the first section 514 andsecond section 518 of the tubular member 510 have contracted axially. Asuturable material (not shown), such as the suturable material 128 shownin FIG. 1, may be disposed about the tubular member 510 and the tubularmember 510 may comprise or be coated with an energy absorptionenhancement material 126, as discussed above. In certain embodiments,the features, dimensions and materials of the annuloplasty ring 500 arethe same as or similar to the features, dimensions and materials of theannuloplasty ring 100 discussed above.

FIG. 6A is a schematic diagram of a top view of a substantially D-shapedwire 600 comprising a shape memory material according to certainembodiments of the invention. The term “wire” is a broad term having itsnormal and customary meaning and includes, for example, mesh, flat,round, rod-shaped, or band-shaped members. Suitable shape memorymaterials include shape memory polymers or shape memory alloysincluding, for example, ferromagnetic shape memory alloys, as discussedabove. The wire 600 comprises a substantially linear portion 608, twocorner portions 610, and a substantially semi-circular portion 612.

For purposes of discussion, the wire 600 is shown relative to a firstreference point 614, a second reference point 616 and a third referencepoint 618. The radius of the substantially semi-circular portion 612 isdefined with respect to the first reference point 614 and the cornerportions 610 are respectively defined with respect to the secondreference point 616 and the third reference point 618. Also for purposesof discussion, FIG. 6A shows a first transverse dimension A, a secondtransverse dimension B.

In certain embodiments, the first transverse dimension A is in a rangebetween approximately 20.0 mm and approximately 40.0 mm, the secondtransverse dimension B is in a range between approximately 10.0 mm andapproximately 25.0 mm. In certain such embodiments, the wire 600comprises a rod having a diameter in a range between approximately 0.45mm and approximately 0.55 mm, the radius of each corner portion 610 isin a range between approximately 5.8 mm and 7.2 mm, and the radius ofthe substantially semi-circular portion 612 is in a range betweenapproximately 11.5 mm and approximately 14.0 mm. In certain other suchembodiments, the wire 600 comprises a rod having a diameter in a rangebetween approximately 0.90 mm and approximately 1.10 mm, the radius ofeach corner portion 610 is in a range between approximately 6.1 mm and7.4 mm, and the radius of the substantially semi-circular portion 612 isin a range between approximately 11.7 mm and approximately 14.3 mm.

In certain other embodiments, the first transverse dimension A is in arange between approximately 26.1 mm and approximately 31.9 mm, thesecond transverse dimension B is in a range between approximately 20.3mm and approximately 24.9 mm. In certain such embodiments, the wire 600comprises a rod having a diameter in a range between approximately 0.4mm and approximately 0.6 mm, the radius of each corner portion 610 is ina range between approximately 6.7 mm and 8.3 mm, and the radius of thesubstantially semi-circular portion 612 is in a range betweenapproximately 13.3 mm and approximately 16.2 mm. In certain other suchembodiments, the wire 600 comprises a rod having a diameter in a rangebetween approximately 0.90 mm and approximately 1.10 mm, the radius ofeach corner portion 610 is in a range between approximately 6.9 mm and8.5 mm, and the radius of the substantially semi-circular portion 612 isin a range between approximately 13.5 mm and approximately 16.5 mm.

In certain embodiments, the wire 600 comprises a NiTi alloy configuredto transition to its austenite phase when heated so as to transform to amemorized shape, as discussed above. In certain such embodiments, thefirst transverse dimension A of the wire 600 is configured to be reducedby approximately 10% to 25% when transitioning to the austenite phase.In certain such embodiments, the austenite start temperature A_(s) is ina range between approximately 33 degrees Celsius and approximately 43degrees Celsius, the austenite finish temperature A_(f) is in a rangebetween approximately 45 degrees Celsius and approximately 55 degreesCelsius, the martensite start temperature M_(s) is less thanapproximately 30 degrees Celsius, and the martensite finish temperatureM_(f) is greater than approximately 20 degrees Celsius. In otherembodiments, the austenite finish temperature A_(f) is in a rangebetween approximately 48.75 degrees Celsius and approximately 51.25degrees Celsius. Other embodiments can include other start and finishtemperatures for martensite, rhombohedral and austenite phases asdescribed herein.

FIGS. 6B-6E are schematic diagrams of side views of the shape memorywire 600 of FIG. 6A according to certain embodiments. In addition toexpanding and/or contracting the first transverse dimension A and/or thesecond transverse dimension B when transitioning to the austenite phase,in certain embodiments the shape memory wire 600 is configured to changeshape in a third dimension perpendicular to the first transversedimension A and the second transverse dimension B. For example, incertain embodiments, the shape memory wire 600 is substantially planaror flat in the third dimension, as shown in FIG. 6B, when implanted intoa patient's body. Then, after implantation, the shape memory wire 600 isactivated such that it expands or contracts in the first transversedimension A and/or the second transverse dimension B and flexes or bowsin the third dimension such that it is no longer planar, as shown inFIG. 6C. Such bowing may be symmetrical as shown in FIG. 6C orasymmetrical as shown in FIG. 6D to accommodate the natural shape of theannulus.

In certain embodiments, the shape memory wire 600 is configured to bowin the third dimension a distance in a range between approximately 2millimeters and approximately 10 millimeters. In certain embodiments,the shape memory wire 600 is implanted so as to bow towards the atriumwhen implanted around a cardiac valve annulus to accommodate the naturalshape of the annulus. In other embodiments, the shape memory wire 600 isconfigured to bow towards the ventricle when implanted around a cardiacvalve to accommodate the natural shape of the annulus.

In certain embodiments, the shape memory wire 600 is bowed in the thirddimension, as shown in FIG. 6C, when implanted into the patient's body.Then, after implantation, the shape memory wire 600 is activated suchthat it expands or contracts in the first transverse dimension A and/orthe second transverse dimension B and further flexes or bows in thethird dimension, as shown in FIG. 6E. In certain other embodiments, theshape memory wire 600 is bowed in the third dimension, as shown in FIG.6C, when implanted into the patient's body. Then, after implantation,the shape memory wire 600 is activated such that it expands or contractsin the first transverse dimension A and/or the second transversedimension B and changes shape in the third dimension so as to becomesubstantially flat, as shown in FIG. 6B. An artisan will recognize fromthe disclosure herein that other annuloplasty rings disclosed herein canalso be configured to bow or change shape in a third dimension so as toaccommodate or further reinforce a valve annulus.

FIG. 7A is a perspective view illustrating portions of an annuloplastyring 700 comprising the wire 600 shown in FIG. 6A according to certainembodiments of the invention. The wire 600 is covered by a flexiblematerial 712 such as silicone rubber and a suturable material 714 suchas woven polyester cloth, Dacron®, woven velour, polyurethane,polytetrafluoroethylene (PTFE), heparin-coated fabric, or otherbiocompatible material. In other embodiments, the suturable material 714comprises a biological material such as bovine or equine pericardium,homograft, patient graft, or cell-seeded tissue. For illustrativepurposes, portions of the flexible material 712 and the suturablematerial 714 are not shown in FIG. 7A to show the wire 600. However, incertain embodiments, the flexible material 712 and the suturablematerial 714 are continuous and cover substantially the entire wire 600.Although not shown, in certain embodiments, the wire 600 is coated withan energy absorption enhancement material, as discussed above.

FIG. 7B is an enlarged perspective view of a portion of the annuloplastyring 700 shown in FIG. 7A. For illustrative purposes, portions of theflexible material 712 are not shown to expose the wire 600 and portionsof the suturable material 714 are shown peeled back to expose theflexible material 712. In certain embodiments, the diameter of theflexible material 712 is in a range between approximately 0.10 inchesand approximately 0.15 inches. FIG. 7B shows the wire 600 substantiallycentered within the circumference of the flexible material 712. However,in certain embodiments, the wire 600 is offset within the circumferenceof the flexible material 712 to allow more space for sutures.

FIG. 8 is a schematic diagram of a substantially C-shaped wire 800comprising a shape memory material according to certain embodiments ofthe invention. Suitable shape memory materials include shape memorypolymers or shape memory alloys including, for example, ferromagneticshape memory alloys, as discussed above. The wire 800 comprises twocorner portions 810, and a substantially semi-circular portion 812.

For purposes of discussion, the wire 800 is shown relative to a firstreference point 814, a second reference point 816 and a third referencepoint 818. The radius of the substantially semi-circular portion 812 isdefined with respect to the first reference point 814 and the cornerportions 810 are respectively defined with respect to the secondreference point 816 and the third reference point 818. Also for purposesof discussion, FIG. 8 shows a first transverse dimension A and a secondtransverse dimension B. In certain embodiments, the wire 800 comprises arod having a diameter and dimensions A and B as discussed above inrelation to FIG. 6A.

In certain embodiments, the wire 800 comprises a NiTi alloy configuredto transition to its austenite phase when heated so as to transform to amemorized shape, as discussed above. In certain such embodiments, thefirst transverse dimension A of the wire 800 is configured to be reducedby approximately 10% to 25% when transitioning to the austenite phase.In certain such embodiments, the austenite start temperature A_(s) is ina range between approximately 33 degrees Celsius and approximately 43degrees Celsius, the austenite finish temperature A_(f) is in a rangebetween approximately 45 degrees Celsius and approximately 55 degreesCelsius, the martensite start temperature M_(s) is less thanapproximately 30 degrees Celsius, and the martensite finish temperatureM_(f) is greater than approximately 20 degrees Celsius. In otherembodiments, the austenite finish temperature A_(f) is in a rangebetween approximately 48.75 degrees Celsius and approximately 51.25degrees Celsius.

FIG. 9A is a perspective view illustrating portions of an annuloplastyring 900 comprising the wire 800 shown in FIG. 8 according to certainembodiments of the invention. The wire 800 is covered by a flexiblematerial 912 such as silicone rubber and a suturable material 914 suchas woven polyester cloth, Dacron®, woven velour, polyurethane,polytetrafluoroethylene (PTFE), heparin-coated fabric, or otherbiocompatible material. In other embodiments, the suturable material 914comprises a biological material such as bovine or equine pericardium,homograft, patient graft, or cell-seeded tissue. For illustrativepurposes, portions of the flexible material 912 and the suturablematerial 914 are not shown in FIG. 9A to show the wire 800. However, incertain embodiments, the flexible material 912 and the suturablematerial 914 cover substantially the entire wire 800. Although notshown, in certain embodiments, the wire 800 is coated with an energyabsorption enhancement material, as discussed above.

FIG. 9B is an enlarged perspective view of a portion of the annuloplastyring 900 shown in FIG. 9A. For illustrative purposes, portions of theflexible material 912 are not shown to expose the wire 800 and portionsof the suturable material 914 are shown peeled back to expose theflexible material 912. In certain embodiments, the diameter of theflexible material 912 is in a range between approximately 0.10 inchesand approximately 0.15 inches. FIG. 9B shows the wire 800 substantiallycentered within the circumference of the flexible material 912. However,in certain embodiments, the wire 800 is offset within the circumferenceof the flexible material 912 to allow more space for sutures.

FIG. 10A is a perspective view illustrating portions of an annuloplastyring 1000 configured to contract and expand according to certainembodiments of the invention. FIG. 10B is a top cross-sectional view ofthe annuloplasty ring 1000. As discussed above, after the annuloplastyring 1000 has been contracted, it may become necessary to expand theannuloplasty ring 1000. For example, the annuloplasty ring 1000 may beimplanted in a child with an enlarged heart. When the size of the heartbegins to recover to its natural size, the annuloplasty ring 1000 can becontracted. Then, as the child gets older and the heart begins to grow,the annuloplasty ring 1000 can be enlarged as needed.

The annuloplasty ring 1000 comprises a first shape memory wire 1010 forcontracting the annuloplasty ring 1000 and a second shape memory wire1012 for expanding the annuloplasty ring 1000. The first and secondshape memory wires, 1010, 1012 are covered by the flexible material 912and the suturable material 914 shown in FIGS. 9A-9B. For illustrativepurposes, portions of the flexible material 912 and the suturablematerial 914 are not shown in FIG. 10A to show the shape memory wires1010, 1012. However, as schematically illustrated in FIG. 10B, incertain embodiments, the flexible material 912 and the suturablematerial 914 substantially cover the first and second shape memory wires1010, 1012. As discussed below, the flexible material 912 operativelycouples the first shape memory wire 1010 and the second shape memorywire 1012 such that a shape change in one will mechanically effect theshape of the other. The first and second shape memory wires 1010, 1012each comprise a shape memory material, such as the shape memorymaterials discussed above. However, the first and second shape memorywires 1010, 1012 are activated at different temperatures.

In certain embodiments, the annuloplasty ring 1000 is heated to a firsttemperature that causes the first shape memory wire 1010 to transitionto its austenite phase and contract to its memorized shape. At the firsttemperature, the second shape memory wire 1012 is in its martensitephase and is substantially flexible as compared the contracted firstshape memory wire 1010. Thus, when the first shape memory wire 1010transitions to its austenite phase, it exerts a sufficient force on thesecond shape memory wire 1012 through the flexible material 912 todeform the second shape memory wire 1012 and cause the annuloplasty ring1000 to contract.

The annuloplasty ring 1000 can be expanded by heating the annuloplastyring to a second temperature that causes the second shape memory wire1012 to transition to its austenite phase and expand to its memorizedshape. In certain embodiments, the second temperature is higher than thefirst temperature. Thus, at the second temperature, both the first andsecond shape memory wires 1010, 1012 are in their respective austenitephases. In certain such embodiments, the diameter of the second shapememory wire 1012 is sufficiently larger than the diameter of the firstshape memory wire 1010 such that the second memory shape wire 1012exerts a greater force to maintain its memorized shape in the austenitephase than the first shape memory wire 1010. Thus, the first shapememory wire 1010 is mechanically deformed by the force of the secondmemory shape wire 1012 and the annuloplasty ring 1000 expands.

In certain embodiments, the first memory shape wire 1010 is configuredto contract by approximately 10% to 25% when transitioning to itsaustenite phase. In certain such embodiments, the first memory shapewire 1010 has an austenite start temperature A_(s) in a range betweenapproximately 33 degrees Celsius and approximately 43 degrees Celsius,an austenite finish temperature A_(f) in a range between approximately45 degrees Celsius and approximately 55 degrees Celsius, a martensitestart temperature M_(s) less than approximately 30 degrees Celsius, anda martensite finish temperature M_(f) greater than approximately 20degrees Celsius. In other embodiments, the austenite finish temperatureA_(f) of the first memory shape wire 1010 is in a range betweenapproximately 48.75 degrees Celsius and approximately 51.25 degreesCelsius.

In certain embodiments, the second memory shape wire 1012 is configuredto expand by approximately 10% to 25% when transitioning to itsaustenite phase. In certain such embodiments, the second memory shapewire 1010 has an austenite start temperature A_(s) in a range betweenapproximately 60 degrees Celsius and approximately 70 degrees Celsius,an austenite finish temperature A_(f) in a range between approximately65 degrees Celsius and approximately 75 degrees Celsius, a martensitestart temperature M_(s) less than approximately 30 degrees Celsius, anda martensite finish temperature M_(f) greater than approximately 20degrees Celsius. In other embodiments, the austenite finish temperatureA_(f) of the first memory shape wire 1010 is in a range betweenapproximately 68.75 degrees Celsius and approximately 71.25 degreesCelsius.

FIG. 11A is a perspective view illustrating portions of an annuloplastyring 1100 according to certain embodiments comprising the first shapememory wire 1010 for contraction, the second shape memory wire 1012 forexpansion, the flexible material 912 and the suturable material 914shown in FIGS. 10A-10B. For illustrative purposes, portions of theflexible material 912 and the suturable material 914 are not shown inFIG. 11A to show the shape memory wires 1010, 1012. However, in certainembodiments, the flexible material 912 and the suturable material 914substantially cover the first and second shape memory wires 1010, 1012.FIG. 11B is an enlarged perspective view of a portion of theannuloplasty ring 1100 shown in FIG. 11A. For illustrative purposes,portions of the flexible material 912 are not shown to expose the firstand second shape memory wires 1010, 1012 and portions of the suturablematerial 914 are shown peeled back to expose the flexible material 912.

The first shape memory wire 1010 comprises a first coating 1120 and thesecond shape memory wire 1012 comprises a second coating 1122. Incertain embodiments, the first coating 1120 and the second coating 1122each comprise silicone tubing configured to provide suture attachment toa heart valve annulus. In certain other embodiments, the first coating1120 and the second coating 1122 each comprise an energy absorptionmaterial, such as the energy absorption materials discussed above. Incertain such embodiments, the first coating 1120 heats when exposed to afirst form of energy and the second coating 1122 heats when exposed to asecond form of energy. For example, the first coating 1120 may heat whenexposed to MRI energy and the second coating 1122 may heat when exposedto HIFU energy. As another example, the first coating 1120 may heat whenexposed to RF energy at a first frequency and the second coating 1122may heat when exposed to RF energy at a second frequency. Thus, thefirst shape memory wire 1010 and the second shape memory wire 1012 canbe activated independently such that one transitions to its austenitephase while the other remains in its martensite phase, resulting incontraction or expansion of the annuloplasty ring 1100.

FIG. 12 is a perspective view of a shape memory wire 800, such as thewire 800 shown in FIG. 8, wrapped in an electrically conductive coil1210 according to certain embodiments of the invention. The coil 1210 iswrapped around a portion of the wire 800 where it is desired to focusenergy and heat the wire 800. In certain embodiments, the coil 1210 iswrapped around approximately 5% to approximately 15% of the wire 800. Inother embodiments, the coil 1210 is wrapped around approximately 15% toapproximately 70% of the wire 800. In other embodiments, the coil 1210is wrapped around substantially the entire wire 800. Although not shown,in certain embodiments, the wire 800 also comprises a coating comprisingan energy absorption material, such as the energy absorption materialsdiscussed above. The coating may or may not be covered by the coil 1210.

As discussed above, an electrical current can be non-invasively inducedin the coil 1210 using electromagnetic energy. For example, in certainembodiments, a handheld or portable device (not shown) comprising anelectrically conductive coil generates an electromagnetic field thatnon-invasively penetrates the patient's body and induces a current inthe coil 1210. The electrical current causes the coil 1210 to heat. Thecoil 1210, the wire 800 and the coating (if any) are thermallyconductive so as to transfer the heat or thermal energy from the coil1210 to the wire 800. Thus, thermal energy can be directed to the wire800, or portions thereof, while reducing thermal damage to surroundingtissue.

FIGS. 13A and 13B show an embodiment of an annuloplasty ring 1310 havinga nominal inner diameter or transverse dimension indicated by arrow 1312and a nominal outer diameter or transverse dimension indicated by arrows1314. The ring 1310 includes a tubular member 1316 having asubstantially round transverse cross section with an internal shapememory member 1318 disposed within an inner chamber 1319 of the tubularmember 1316. The internal shape memory member 1318 is a ribbon or wirebent into a series of interconnected segments 1320. Upon heating of thetubular member 1316 and the internal shape memory member 1318, the innertransverse dimension 1312 becomes smaller due to axial shortening of thetubular member 1316 and an inward radial force applied to an innerchamber surface 1322 of the tubular member 1316 by the internal shapememory member 1318. The internal shape memory member 1318 is expandedupon heating such that the ends of segments 1320 push against the innerchamber surface 1322 and outer chamber surface 1324, as shown by arrow1326 in FIG. 13B, and facilitate radial contraction of the innertransverse dimension 1312. Thus, activation of the internal shape memorymember 1318 changes the relative distance between the against the innerchamber surface 1322 and outer chamber surface 1324.

Although not shown in FIG. 13A or 13B, The inner shape memory member1318 may also have a heating energy absorption enhancement material,such as one or more of the energy absorption enhancement materialsdiscussed above, disposed about it within the inner chamber 1319. Theenergy absorption material may also be coated on an outer surface and/oran inner surface of the tubular member 1316. The inner transversedimension 1312 of the ring 1310 in FIG. 13B is less than the innertransverse dimension 1312 of the ring 1310 shown in FIG. 13A. However,according to certain embodiments, the outer transverse dimension 1314 issubstantially constant in both FIGS. 13A and 13B.

For some indications, it may be desirable for an adjustable annuloplastyring to have some compliance in order to allow for expansion andcontraction of the ring in concert with the expansion and contraction ofthe heart during the beating cycle or with the hydrodynamics of thepulsatile flow through the valve during the cycle. As such, it may bedesirable for an entire annuloplasty ring, or a section or sectionsthereof, to have some axial flexibility to allow for some limited andcontrolled expansion and contraction under clinical conditions. FIGS. 14and 15 illustrate embodiments of adjustable annuloplasty rings thatallow some expansion and contraction in a deployed state.

FIG. 14 shows an annuloplasty ring 1400 that is constructed in such away that it allows mechanical expansion and compression of the ring 1400under clinical conditions. The ring 1400 includes a coil 1412 made of ashape memory material, such as one or more of the shape memory materialsdiscussed above. The shape memory material or other portion of the ring1400 may be coated with an energy absorption material, such as theenergy absorption materials discussed above. The coil 1412 may have atypical helical structure of a normal spring wire coil, oralternatively, may have another structure such as a ribbon coil. Incertain embodiments, the coil 1412 is surrounded by a suturable material128, such as Dacron® or the other suturable materials discussed herein.The coiled structure or configuration of the coil 1412 allows the ring1400 to expand and contract slightly when under physiological pressuresand forces from heart dynamics or hydrodynamics of blood flow through ahost heart valve.

For embodiments where the coil 1412 is made of NiTi alloy or other shapememory material, the ring 1400 is responsive to temperature changeswhich may be induced by the application of heating energy on the coil1412. In certain embodiments, if the temperature is raised, the coil1412 will contract axially or circumferentially such that an innertransverse dimension of the ring 1400 decreases, as shown by the dashedlines in FIG. 14. In FIG. 14, reference 1412′ represents the coil 1412in its contracted state and reference 128′ represents the suturablematerial 128 in its contracted state around the contracted coil 1412′.In addition, or in other embodiments, the coil 1412 expands axially orcircumferentially such that the inner transverse dimension of the ring1400 increases. Thus, in certain embodiments, the ring 1400 can beexpanded and contracted by applying invasive or non-invasive energythereto.

FIG. 15 illustrates another embodiment of an adjustable annuloplastyring 1500 that has dynamic compliance with dimensions, features andmaterials that may be the same as or similar to those of ring 1400.However, the ring 1500 has a zig-zag ribbon member 1510 in place of thecoil 1412 in the embodiment of FIG. 14. In certain embodiments, if thetemperature is raised, the ribbon member 1510 will contract axially orcircumferentially such that an inner transverse dimension of the ring1500 decreases, as shown by the dashed lines in FIG. 15. In FIG. 15,reference 1510′ represents the ribbon member 1510 in its contractedstate and reference 128′ represents the suturable material 128 in itscontracted state around the contracted ribbon member 1510′. In addition,or in other embodiments, the ribbon member 1510 expands axially orcircumferentially such that the inner transverse dimension of the ring1500 increases. Thus, in certain embodiments, the ring 1500 can beexpanded and contracted by applying invasive or non-invasive energythereto.

The embodiments of FIGS. 14 and 15 may have a substantially circularconfiguration as shown in the figures, or may have D-shaped or C-shapedconfigurations as shown with regard to other embodiments discussedabove. In certain embodiments, the features, dimensions and materials ofrings 1400 and 1500 are the same as or similar to the features,dimensions and materials of the annuloplasty ring 400 discussed above.

FIGS. 16A and 16B illustrate an annuloplasty ring 1600 according tocertain embodiments that has a substantially circular shape orconfiguration when in the non-activated state shown in FIG. 16A. Thering 1600 comprises shape memory material or materials which areseparated into a first temperature response zone 1602, a secondtemperature response zone 1604, a third temperature response zone 1606and a fourth temperature response zone 1608. The zones are axiallyseparated by boundaries 1610. Although the ring 1600 is shown with fourzones 1602, 1604, 1606, 1608, an artisan will recognize from thedisclosure herein that other embodiments may include two or more zonesof the same or differing lengths. For example, one embodiment of anannuloplasty ring 1600 includes approximately three to approximatelyeight temperature response zones.

In certain embodiments, the shape memory materials of the varioustemperature response zones 1602, 1604, 1606, 1608 are selected to havetemperature responses and reaction characteristics such that a desiredshape and configuration can be achieved in vivo by the application ofinvasive or non-invasive energy, as discussed above. In addition togeneral contraction and expansion changes, more subtle changes in shapeand configuration for improvement or optimization of valve function orhemodynamics may be achieved with such embodiments.

According to certain embodiments, the first zone 1602 and second zone1604 of the ring 1600 are made from a shape memory material having afirst shape memory temperature response. The third zone 1606 and fourthzone 1608 are made from a shape memory material having a second shapememory temperature response. In certain embodiments, the four zonescomprise the same shape memory material, such as NiTi alloy or othershape memory material as discussed above, processed to produce thevaried temperature response in the respective zones. In otherembodiments, two or more of the zones may comprise different shapememory materials. Certain embodiments include a combination of shapememory alloys and shape memory polymers in order to achieve the desiredresults.

According to certain embodiments, FIG. 16B shows the ring 1600 afterheat activation such that it comprises expanded zones 1606′, 1608′corresponding to the zones 1606, 1608 shown in FIG. 16A. Asschematically shown in FIG. 16A, activation has expanded the zones1606′, 1608′ so as to increase the axial lengths of the segments of thering 1600 corresponding to those zones. In addition, or in otherembodiments, the zones 1606 and 1608 are configured to contract by asimilar percentage instead of expand. In other embodiments, the zones1602, 1604, 1606, 1608 are configured to each have a different shapememory temperature response such that each segment corresponding to eachzone 1602, 1604, 1606, 1608 could be activated sequentially.

FIG. 16B schematically illustrates that the zones 1606′, 1608′ haveexpanded axially (i.e., from their initial configuration as shown by thezones 1606, 1608 in FIG. 16A). In certain embodiments, the zones 1602,1604 are configured to be thermally activated to remember a shape memorydimension or size upon reaching a temperature in a range betweenapproximately 51 degrees Celsius and approximately 60 degrees Celsius.In certain such embodiments, the zones 1606 and 1608 are configured torespond at temperatures in a range between approximately 41 degreesCelsius and approximately 48 degrees Celsius. Thus, for example, byapplying invasive or non-invasive energy, as discussed above, to thering 1600 until the ring 1600 reaches a temperature of approximately 41degrees Celsius to approximately 48 degrees Celsius, the zones 1606,1608 will respond by expanding or contracting by virtue of the shapememory mechanism, and the zones 1602, 1604 will not.

In certain other embodiments, the zones 1602, 1604 are configured toexpand or contract by virtue of the shape memory mechanism at atemperature in a range between approximately 50 degrees Celsius andapproximately 60 degrees Celsius. In certain such embodiments, the zones1606, 1608 are configured to respond at a temperature in a range betweenapproximately 39 degrees Celsius and approximately 45 degrees Celsius.

In certain embodiments, the materials, dimensions and features of theannuloplasty ring 1600 and the corresponding zones 1602, 1604, 1606,1608 have the same or similar features, dimensions or materials as thoseof the other ring embodiments discussed above. In certain embodiments,the features of the annuloplasty ring 1600 are added to the embodimentsdiscussed above.

FIGS. 17A and 17B illustrate an annuloplasty ring 1700 according tocertain embodiments that is similar to the annuloplasty ring 1600discussed above, but having a “D-shaped” configuration. The ring 1700comprises shape memory material or materials which are separated into afirst temperature response zone 1714, a second temperature response zone1716, a third temperature response zone 1718 and a fourth temperatureresponse zone 1720. The segments defined by the zones 1714, 1716, 1718,1720 are separated by boundaries 1722. Other than the D-shapedconfiguration, the ring 1700 according to certain embodiments has thesame or similar features, dimensions and materials as the features,dimension and materials of the ring 1600 discussed above.

According to certain embodiments, FIG. 17B shows the ring 1700 afterheat activation such that it comprises expanded zones 1718′, 1720′corresponding to the zones 1718, 1720 shown in FIG. 17A. Asschematically shown in FIG. 17B, activation has expanded the zones1718′, 1720′ by virtue of the shape memory mechanism. The zones 1718,1720 could also be selectively shrunk or contracted axially by virtue ofthe same shape memory mechanism for an embodiment having a rememberedshape smaller than the nominal shape shown in FIG. 17A. The transversecross sections of the rings 1600 and 1700 are substantially round, butcan also have any other suitable transverse cross sectionalconfiguration, such as oval, square, rectangular or the like.

In certain situations, it is advantageous to reshape a heart valveannulus in one dimension while leaving another dimension substantiallyunchanged or reshaped in a different direction. For example, FIG. 18 isa sectional view of a mitral valve 1810 having an anterior (aortic)leaflet 1812, a posterior leaflet 1814 and an annulus 1816. The anteriorleaflet 1812 and the posterior leaflet 1814 meet at a first commissure1818 and a second commissure 1820. When healthy, the annulus 1816encircles the leaflets 1812, 1814 and maintains their spacing to provideclosure of a gap 1822 during left ventricular contraction. When theheart is not healthy, the leaflets 1812, 1814 do not achieve sufficientcoaptation to close the gap 1822, resulting in regurgitation. In certainembodiments, the annulus 1816 is reinforced so as to push the anteriorleaflet 1812 and the posterior leaflet 1814 closer together withoutsubstantially pushing the first commissure 1818 and the secondcommissure 1820 toward one another.

FIG. 18 schematically illustrates an exemplary annuloplasty ring 1826comprising shape memory material configured to reinforce the annulus1816 according to certain embodiments of the invention. For illustrativepurposes, the annuloplasty ring 1826 is shown in an activated statewherein it has transformed to a memorized configuration upon applicationof invasive or non-invasive energy, as described herein. While theannuloplasty ring 1826 is substantially C-shaped, an artisan willrecognize from the disclosure herein that other shapes are possibleincluding, for example, a continuous circular, oval or D-shaped ring.

In certain embodiments, the annuloplasty ring 1826 comprises a firstmarker 1830 and a second marker 1832 that are aligned with the firstcommissure 1818 and the second commissure 1820, respectively, when theannuloplasty ring 1826 is implanted around the mitral valve 1810. Incertain embodiments, the first marker 1830 and the second marker 1832comprise materials that can be imaged in-vivo using standard imagingtechniques. For example, in certain embodiments, the markers 1830comprise radiopaque markers or other imaging materials, as is known inthe art. Thus, the markers 1830, 1832 can be used for subsequentprocedures for alignment with the annuloplasty ring 1826 and/or thecommissures 1818, 1820. For example, the markers 1830, 1832 can be usedto align a percutaneous energy source, such as a heated balloon insertedthrough a catheter, with the annuloplasty ring 1826.

When the shape memory material is activated, the annuloplasty ring 1826contracts in the direction of the arrow 1824 to push the anteriorleaflet 1812 toward the posterior leaflet 1814. Such anterior/posteriorcontraction improves the coaptation of the leaflets 1812, 1814 such thatthe gap 1824 between the leaflets 1812, 1814 sufficiently closes duringleft ventricular contraction. In certain embodiments, the annuloplastyring 1826 also expands in the direction of arrows 1834. Thus, the firstcommissure 1818 and the second commissure 1820 are pulled away from eachother, which draws the leaflets 1812, 1814 closer together and furtherimproves their coaptation. However, in certain other embodiments, theannuloplasty ring does not expand in the direction of the arrows 1834.In certain such embodiments, the distance between the lateral portionsof the annuloplasty ring 1826 between the anterior portion and theposterior portion (e.g., the lateral portions approximately correspondto the locations of the markers 1830, 1832 in the embodiment shown inFIG. 18) remains substantially the same after the shape memory materialis activated.

FIG. 19 is a schematic diagram of a substantially C-shaped wirecomprising a shape memory material configured to contract in a firstdirection and expand in a second direction according to certainembodiments of the invention. Suitable shape memory materials includeshape memory polymers or shape memory alloys including, for example,ferromagnetic shape memory alloys, as discussed above. FIG. 19schematically illustrates the wire 800 in its activated configuration ormemorized shape. For illustrative purposes, the wire 800 is shownrelative to dashed lines representing its deformed shape orconfiguration when implanted into a body before activation.

When the shape memory material is activated, the wire 800 is configuredto respond by contracting in a first direction as indicated by arrow1824. In certain embodiments, the wire 800 also expands in a seconddirection as indicated by arrows 1834. Thus, the wire 800 is usable bythe annuloplasty ring 1826 shown in FIG. 18 to improve the coaptation ofthe leaflets 1812, 1814 by contracting the annulus 1816 in theanterior/posterior direction. In certain embodiments, theanterior/posterior contraction is in a range between approximately 10%and approximately 20%. In certain embodiments, only a first portion 1910and a second portion 1912 of the wire 800 comprise the shape memorymaterial. When the shape memory material is activated, the first portion1910 and the second portion 1912 of the wire 800 are configured torespond by transforming to their memorized configurations and reshapingthe wire 800 as shown.

FIGS. 20A and 20B are schematic diagrams of a body member 2000 accordingto certain embodiments usable by an annuloplasty ring, such as theannuloplasty ring 1826 shown in FIG. 18. Although not shown, in certainembodiments, the body member 2000 is covered by a flexible material suchas silicone rubber and a suturable material such as woven polyestercloth, Dacron®, woven velour, polyurethane, polytetrafluoroethylene(PTFE), heparin-coated fabric, or other biocompatible material, asdiscussed above.

The body member 2000 comprises a wire 2010 and a shape memory tube 2012.As used herein, the terms “tube,” “tubular member” and “tubularstructure” are broad terms having at least their ordinary and customarymeaning and include, for example, hollow elongated structures that mayin cross-section be cylindrical, elliptical, polygonal, or any othershape. Further, the hollow portion of the elongated structure may befilled with one or more materials that may be the same as and/ordifferent than the material of the elongated structure. In certainembodiments, the wire 2010 comprises a metal or metal alloy such asstainless steel, titanium, platinum, combinations of the foregoing, orthe like. In certain embodiments, the shape memory tube 2012 comprisesshape memory materials formed in a tubular structure through which thewire 2010 is inserted. In certain other embodiments, the shape memorytube 2012 comprises a shape memory material coated over the wire 2010.Suitable shape memory materials include shape memory polymers or shapememory alloys including, for example, ferromagnetic shape memory alloys,as discussed above. Although not shown, in certain embodiments, the bodymember 2000 comprises an energy absorption enhancement material, asdiscussed above.

FIG. 20A schematically illustrates the body member 2000 in a firstconfiguration or shape and FIG. 20B schematically illustrates the bodymember 2000 in a second configuration or shape after the shape memorytube has been activated. For illustrative purposes, dashed lines in FIG.20B also show the first configuration of the body member 2000. When theshape memory material is activated, the shape memory tube 2012 isconfigured to respond by contracting in a first direction as indicatedby arrow 1824. In certain embodiments, the shape memory tube 2012 isalso configured to expand in a second direction as indicated by arrows1834. The transformation of the shape memory tube 2012 exerts a force onthe wire 2010 so as to change its shape. Thus, the body member 2000 isusable by the annuloplasty ring 1826 shown in FIG. 18 to pull thecommissures 1818, 1820 further apart and push the leaflets 1812, 1814closer together to improve coaptation.

FIGS. 21A and 21B are schematic diagrams of a body member 2100 accordingto certain embodiments usable by an annuloplasty ring, such as theannuloplasty ring 1826 shown in FIG. 18. Although not shown, in certainembodiments, the body member 2100 is covered by a flexible material suchas silicone rubber and a suturable material such as woven polyestercloth, Dacron®, woven velour, polyurethane, polytetrafluoroethylene(PTFE), heparin-coated fabric, or other biocompatible material, asdiscussed above.

The body member 2100 comprises a wire 2010, such as the wire 2010 shownin FIGS. 20A and 20B and a shape memory tube 2112. As schematicallyillustrated in FIGS. 21A and 21B, the shape memory tube 2112 is sizedand configured to cover a certain percentage of the wire 2010. However,an artisan will recognize from the disclosure herein that in otherembodiments the shape memory tube 2112 may cover other percentages ofthe wire 2010. Indeed, FIGS. 22A and 22B schematically illustrateanother embodiment of a body member 2200 comprising a shape memory tube2112 covering a substantial portion of a wire 2010. The amount ofcoverage depends on such factors as the particular application, thedesired shape change, the shape memory materials used, the amount offorce to be exerted by the shape memory tube 2112 when changing shape,combinations of the foregoing, and the like. For example, in certainembodiments where, as in FIGS. 22A and 22B, the shape memory tube 2112covers a substantial portion of a wire 2010, portions of the shapememory tube 2112 are selectively heated to reshape the wire 2010 at aparticular location. In certain such embodiments, HIFU energy isdirected towards, for example, the left side of the shape memory tube2112, the right side of the shape memory tube 2112, the bottom side ofthe shape memory tube 2112, or a combination of the foregoing toactivate only a portion of the shape memory tube 2112. Thus, the bodymember 2200 can be reshaped one or more portions at a time to allowselective adjustments.

In certain embodiments, the shape memory tube 2112 comprises a firstshape memory material 2114 and a second shape memory material 2116formed in a tubular structure through which the wire 2010 is inserted.In certain such embodiments, the first shape memory material 2114 andthe second shape memory material 2116 are each configured as asemi-circular portion of the tubular structure. For example, FIG. 23 isa transverse cross-sectional view of the body member 2100. Asschematically illustrated in FIG. 23, the first shape memory material2114 and the second shape memory material 2116 are joined at a firstboundary 2310 and a second boundary 2312. In certain embodiments,silicone tubing (not shown) holds the first shape memory material 2114and the second shape memory material 2116 together. In certain otherembodiments, the first shape memory material 2114 and the second shapememory material 2116 each comprise a shape memory coating coveringopposite sides of the wire 2010. Suitable shape memory materials includeshape memory polymers or shape memory alloys including, for example,ferromagnetic shape memory alloys, as discussed above. Although notshown, in certain embodiments the body member 2100 comprises an energyabsorption enhancement material, as discussed above.

FIG. 21A schematically illustrates the body member 2100 in a firstconfiguration or shape before the first shape memory material 2114 andthe second shape memory material 2116 are activated. In certainembodiments, the first shape memory material 2114 and the second shapememory material 2116 are configured to be activated or return to theirrespective memorized shapes at different temperatures. Thus, the firstshape memory material 2114 and the second shape memory material 2116 canbe activated at different times to selectively expand and/or contractthe body member 2100. For example, in certain embodiments, the secondshape memory material 2116 is configured to be activated at a lowertemperature than the first shape memory material 2114.

FIG. 21B schematically illustrates the body member 2100 in a secondconfiguration or shape after the second shape memory material 2116 hasbeen activated. For illustrative purposes, dashed lines in FIG. 21B alsoshow the first configuration of the body member 2100. When the secondshape memory material 2116 is activated, it responds by bending the bodymember 2100 in a first direction as indicated by arrow 1824. In certainembodiments, activation also expands the body member 2100 in a seconddirection as indicated by arrows 1834. Thus, the body member 2100 isusable by the annuloplasty ring 1826 shown in FIG. 18 to pull thecommissures 1818, 1820 further apart and push the leaflets 1812, 1814closer together to improve coaptation.

In certain embodiments, the first shape memory material 2114 can then beactivated to bend the body member 2100 opposite to the first directionas indicated by arrow 2118. In certain such embodiments, the body member2100 is reshaped to the first configuration as shown in FIG. 21A (or thedashed lines in FIG. 21B). Thus, for example, if the size of thepatient's heart begins to grow again (e.g., due to age or illness), thebody member 2100 can be enlarged to accommodate the growth. In certainother embodiments, activation of the first shape memory material 2114further contracts the body member 2100 in the direction of the arrow1824. In certain embodiments, the first shape memory material 2114 hasan austenite start temperature A_(s) in a range between approximately 42degrees Celsius and approximately 50 degrees Celsius and the secondshape memory material 2116 has an austenite start temperature A_(s) in arange between approximately 38 degrees Celsius and 41 degrees Celsius.

FIG. 24 is a perspective view of a body member 2400 usable by anannuloplasty ring according to certain embodiments comprising a firstshape memory band 2410 and a second shape memory band 2412. Suitableshape memory materials for the bands 2410, 2412 include shape memorypolymers or shape memory alloys including, for example, ferromagneticshape memory alloys, as discussed above. Although not shown, in certainembodiments the body member 2100 comprises an energy absorptionenhancement material, as discussed above. Although not shown, in certainembodiments, the body member 2100 is covered by a flexible material suchas silicone rubber and a suturable material such as woven polyestercloth, Dacron®, woven velour, polyurethane, polytetrafluoroethylene(PTFE), heparin-coated fabric, or other biocompatible material, asdiscussed above.

The first shape memory band 2410 is configured to loop back on itself toform a substantially C-shaped configuration. However, an artisan willrecognize from the disclosure herein that the first shape memory band2410 can be configured to loop back on itself in other configurationsincluding, for example, circular, D-shaped, or other curvilinearconfigurations. When activated, the first shape memory band 2410 expandsor contracts such that overlapping portions of the band 2410 slide withrespect to one another, changing the overall shape of the body member2400. The second shape memory band 2412 is disposed along a surface ofthe first shape memory band 2410 such that the second shape memory band2412 is physically deformed when the first shape memory band 2410 isactivated, and the first shape memory band 2410 is physically deformedwhen the second shape memory band 2412 is activated.

As shown in FIG. 24, in certain embodiments at least a portion of thesecond shape memory band 2412 is disposed between overlapping portionsof the first shape memory band 2410. An artisan will recognize from thedisclosure herein, however, that the second shape memory band 2412 maybe disposed adjacent to an outer surface or an inner surface of thefirst shape memory band 2410 rather than between overlapping portions ofthe first shape memory band 2410. When the second shape memory band 2412is activated, it expands or contracts so as to slide with respect to thefirst shape memory band 2410. In certain embodiments, the first shapememory band 2410 and the second shape memory band 2412 are held inrelative position to one another by the flexible material and/orsuturable material discussed above.

While the first shape memory band 2410 and the second shape memory band2412 shown in FIG. 24 are substantially flat, an artisan will recognizefrom the disclosure herein that other shapes are possible including, forexample, rod-shaped wire. However, in certain embodiments the firstshape memory band 2410 and the second shape memory band 2412advantageously comprise substantially flat surfaces configured to guideone another during expansion and/or contraction. Thus, the surface areaof overlapping portions of the first shape memory band 2410 and/or thesecond shape memory band 2412 guide the movement of the body member 2400in a single plane and reduce misalignment (e.g., twisting or moving in avertical plane) during shape changes. The surface area of overlappingportions also advantageously increases support to a heart valve byreducing misalignment during beating of the heart.

An artisan will recognize from the disclosure herein that certainembodiments of the body member 2400 may not comprise either the firstshape memory band 2410 or the second shape memory band 2412. Forexample, in certain embodiments the body member 2400 does not includethe second shape memory band 2412 and is configured to expand and/orcontract by only activating the first shape memory band 2410. Further,an artisan will recognize from the disclosure herein that either thefirst band 2410 or the second band 2412 may not comprise a shape memorymaterial. For example, the first band 2410 may titanium, platinum,stainless steel, combinations of the foregoing, or the like and may beused with or without the second band 2412 to support a coronary valveannulus.

As schematically illustrated in FIGS. 25A-25C, in certain embodimentsthe body member 2400 is configured to change shape at least twice byactivating both the first shape memory band 2410 and the second shapememory band 2412. FIG. 25A schematically illustrates the body member2400 in a first configuration or shape before the first shape memoryband 2410 or the second shape memory band 2412 are activated. In certainembodiments, the first shape memory band 2410 and the second shapememory band 2412 are configured to be activated or return to theirrespective memorized shapes at different temperatures. Thus, the firstshape memory band 2410 and the second shape memory band 2412 can beactivated at different times to selectively expand and/or contract thebody member 2400. For example (and for purposes of discussing FIGS.25A-25C), in certain embodiments, the first shape memory band 2410 isconfigured to be activated at a lower temperature than the second shapememory band 2412. However, an artisan will recognize from the disclosureherein that in other embodiments the second shape memory band 2412 maybe configured to be activated at a lower temperature than the firstshape memory band 2410.

FIG. 25B schematically illustrates the body member 2400 in a secondconfiguration or shape after the first shape memory band 2410 has beenactivated. When the first shape memory band 2410 is activated, itresponds by bending the body member 2400 in a first direction asindicated by arrow 1824. In certain embodiments, the activation alsoexpands the body member 2400 in a second direction as indicated byarrows 1834. Thus, the body member 2400 is usable by the annuloplastyring 1826 shown in FIG. 18 to pull the commissures 1818, 1820 furtherapart and push the leaflets 1812, 1814 closer together to improvecoaptation.

In certain embodiments, the second shape memory band 2412 can then beactivated to further contract the body member 2400 in the direction ofthe arrow 1824 and, in certain embodiments, further expand the bodymember 2400 in the direction of arrows 1834. In certain suchembodiments, activating the second shape memory band 2412 reshapes thebody member 2400 to a third configuration as shown in FIG. 25C. Thus,for example, as the patient's heart progressively heals and reduces insize, the body member 2400 can be re-sized to provide continued supportand improved leaflet coaptation. In certain other embodiments,activation of the second shape memory band 2412 bends the body member2400 opposite to the first direction as indicated by arrow 2118. Incertain such embodiments, activating the second shape memory band 2412reshapes the body member 2400 to the first configuration as shown inFIG. 25A. Thus, for example, if the size of the patient's heart beginsto grow again (e.g., due to age or illness), the body member 2400 can bere-sized to accommodate the growth.

In certain annuloplasty ring embodiments, flexible materials and/orsuturable materials used to cover shape memory materials also thermallyinsulate the shape memory materials so as to increase the time requiredto activate the shape memory materials through application of thermalenergy. Thus, surrounding tissue is exposed to the thermal energy forlonger periods of time, which may result in damage to the surroundingtissue. Therefore, in certain embodiments of the invention, thermallyconductive materials are configured to penetrate the flexible materialsand/or suturable materials so as to deliver thermal energy to the shapememory materials such that the time required to activate the shapememory materials is decreased.

For example, FIG. 26 is a perspective view illustrating an annuloplastyring 2600 comprising one or more thermal conductors 2610, 2612, 2614according to certain embodiments of the invention. The annuloplasty ring2600 further comprises a shape memory wire 800 covered by a flexiblematerial 912 and a suturable material 914, such as the wire 800, theflexible material 912 and the suturable material 914 shown in FIG. 9A.As shown in FIG. 26, in certain embodiments, the shape memory wire 800is offset from the center of the flexible material 912 to allow moreroom for sutures to pass through the flexible material 912 and suturablematerial 914 to attach the annuloplasty ring 2600 to a cardiac valve. Incertain embodiments, the flexible material 912 and/or the suturablematerial 914 are thermally insulative. In certain such embodiments, theflexible material 912 comprises a thermally insulative material.Although the annuloplasty ring 2600 is shown in FIG. 26 as substantiallyC-shaped, an artisan will recognize from the disclosure herein that theone or more thermal conductors 2610, 2612, 2614 can also be used withother configurations including, for example, circular, D-shaped, orother curvilinear configurations.

In certain embodiments, the thermal conductors 2610, 2612, 2614 comprisea thin (e.g., having a thickness in a range between approximately 0.002inches and approximately 0.015 inches) wire wrapped around the outsideof the suturable material 914 and penetrating the suturable material 914and the flexible material 912 at one or more locations 2618 so as totransfer externally applied heat energy to the shape memory wire 800.For example, FIGS. 27A-27C are transverse cross-sectional views of theannuloplasty ring 2600 schematically illustrating exemplary embodimentsfor conducting thermal energy to the shape memory wire 800. In theexemplary embodiment shown in FIG. 27A, the thermal conductor 2614 wrapsaround the suturable material 914 one or more times, penetrates thesuturable material 914 and the flexible material 912, passes around theshape memory wire 800, and exits the flexible material 912 and thesuturable material 914. In certain embodiments, the thermal conductor2614 physically contacts the shape memory wire 800. However, in otherembodiments, the thermal conductor 2614 does not physically contact theshape memory wire 800 but passes sufficiently close to the shape memorywire 800 so as to decrease the time required to activate the shapememory wire 800. Thus, the potential for thermal damage to surroundingtissue is reduced.

In the exemplary embodiment shown in FIG. 27B, the thermal conductor2614 wraps around the suturable material 914 one or more times,penetrates the suturable material 914 and the flexible material 912,passes around the shape memory wire 800 two or more times, and exits theflexible material 912 and the suturable material 914. By passing aroundthe shape memory wire 800 two or more times, the thermal conductor 2614concentrates more energy in the area of the shape memory wire 800 ascompared to the exemplary embodiment shown in FIG. 27A. Again, thethermal conductor 2614 may or may not physically contact the shapememory wire 800.

In the exemplary embodiment shown in FIG. 27C, the thermal conductor2614 wraps around the suturable material 914 one or more times andpasses through the suturable material 914 and the flexible material 912two or more times. Thus, portions of the thermal conductor 2614 aredisposed proximate the shape memory wire 800 so as to transfer heatenergy thereto. Again, the thermal conductor 2614 may or may notphysically contact the shape memory wire 800. An artisan will recognizefrom the disclosure herein that one or more of the exemplary embodimentsshown in FIGS. 27A-27C can be combined and that the thermal conductor2614 can be configured to penetrate the suturable material 914 and theflexible material 912 in other ways in accordance with the invention soas to transfer heat to the shape memory wire 800.

Referring again to FIG. 26, in certain embodiments the locations of thethermal conductors 2610, 2612, 2614 are selected based at least in parton areas where energy will be applied to activate the shape memory wire800. For example, in certain embodiments heat energy is appliedpercutaneously through a balloon catheter and the thermal conductors2610, 2612, 2614 are disposed on the surface of the suturable material914 in locations likely to make contact with the inflated balloon.

In addition, or in other embodiments, the thermal conductors 2610, 2612,2614 are located so as to mark desired positions on the annuloplastyring 2600. For example, the thermal conductors 2610, 2612, 2614 may bedisposed at locations on the annuloplasty ring 2600 corresponding tocommissures of heart valve leaflets, as discussed above with respect toFIG. 18. As another example, the thermal conductors 2610, 2612, 2614 canbe used to align a percutaneous energy source, such as a heated ballooninserted through a catheter, with the annuloplasty ring 2600. In certainsuch embodiments the thermal conductors 2610, 2612, 2614 compriseradiopaque materials such as gold, copper or other imaging materials, asis known in the art.

FIG. 28 is a schematic diagram of an annuloplasty ring 2800 according tocertain embodiments of the invention comprising one or more thermalconductors 2810, 2812, 2814, 2816, 2818, such as the thermal conductors2610, 2612, 2614 shown in FIG. 26. As schematically illustrated in FIG.28, the annuloplasty ring 2800 further comprises a shape memory wire 800covered by a flexible material 912 and a suturable material 914, such asthe wire 800, the flexible material 912 and the suturable material 914shown in FIG. 9A.

In certain embodiments, the shape memory wire 800 is not sufficientlythermally conductive so as to quickly transfer heat applied in the areasof the thermal conductors 2810, 2812, 2814, 2816, 2818. Thus, in certainsuch embodiments, the annuloplasty ring 2800 comprises a thermalconductor 2820 that runs along the length of the shape memory wire 800so as to transfer heat to points of the shape memory wire 800 extendingbeyond or between the thermal conductors 2810, 2812, 2814, 2816, 2818.In certain embodiments, each of the thermal conductors 2810, 2812, 2814,2816, 2818, comprise a separate thermally conductive wire configured totransfer heat to the thermal conductive wire 2820. However, in certainother embodiments, at least two of the thermal conductors 2810, 2812,2814, 2816, 2818 and the thermal conductor 2820 comprise one continuousthermally conductive wire.

Thus, thermal energy can be quickly transferred to the annuloplasty ring2600 or the annuloplasty ring 2800 to reduce the amount of energyrequired to activate the shape memory wire 800 and to reduce thermaldamage to the patient's surrounding tissue.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the inventions. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the inventions. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the inventions.

1. An adjustable annuloplasty ring comprising: a first shape memorymember configured to transform said annuloplasty ring from a firstconfiguration having a first size of a ring dimension to a secondconfiguration having a second size of the ring dimension, wherein saidsecond size is less than said first size; and a second shape memorymember configured to transform said annuloplasty ring from said secondconfiguration to a third configuration having a third size of the ringdimension, wherein said second size is less than said third size.
 2. Theadjustable annuloplasty ring of claim 1, wherein said first shape memorymember is configured to change shape in response to being heated to afirst temperature, and wherein said second shape memory member isconfigured to change shape in response to being heated to a secondtemperature.
 3. The adjustable annuloplasty ring of claim 2, whereinsaid first temperature is lower than said second temperature.
 4. Theadjustable annuloplasty ring of claim 2, wherein said second temperatureis lower than said first temperature.
 5. The adjustable annuloplastyring of claim 2, wherein at least one of said first shape memory memberand said second shape memory member comprises at least one of a metal, ametal alloy, a nickel titanium alloy, a shape memory polymer, polylacticacid, and polyglycolic acid.
 6. The adjustable annuloplasty ring ofclaim 1, wherein at least one of said first shape memory member and saidsecond shape memory member is configured to change shape in response toa magnetic field.
 7. The adjustable annuloplasty ring of claim 6,wherein at least one of said first shape memory member and said secondshape memory member comprises at least one of Fe—C, Fe—Pd, Fe—Mn—Si,Co—Mn, Fe—Co—Ni—Ti, Ni—Mn—Ga, Ni₂MnGa, and Co—Ni—Al.
 8. The adjustableannuloplasty ring of claim 1, wherein said ring dimension is aseptolateral dimension.
 9. An adjustable annuloplasty ring comprising: afirst shape memory member configured to transform said annuloplasty ringfrom a first configuration having a first size of a ring dimension to asecond configuration having a second size of the ring dimension, whereinsaid second size is less than said first size; and a second shape memorymember configured to transform said annuloplasty ring from said secondsize to a third size of the ring dimension, wherein said third size isless than said second size.
 10. The adjustable annuloplasty ring ofclaim 9, wherein said first shape memory member is configured to changeshape in response to being heated to a first temperature, and whereinsaid second shape memory member is configured to change shape inresponse to being heated to a second temperature.
 11. The adjustableannuloplasty ring of claim 10, wherein said first temperature is lowerthan said second temperature.
 12. The adjustable annuloplasty ring ofclaim 10, wherein said second temperature is lower than said firsttemperature.
 13. The adjustable annuloplasty ring of claim 10, whereinat least one of said first shape memory member and said second shapememory member comprises at least one of a metal, a metal alloy, a nickeltitanium alloy, a shape memory polymer, polylactic acid, andpolyglycolic acid.
 14. The adjustable annuloplasty ring of claim 9,wherein at least one of said first shape memory member and said secondshape memory member is configured to change shape in response to amagnetic field.
 15. The adjustable annuloplasty ring of claim 14,wherein at least one of said first shape memory member and said secondshape memory member comprises at least one of Fe—C, Fe—Pd, Fe—Mn—Si,Co—Mn, Fe—Co—Ni—Ti, Ni—Mn—Ga, Ni₂MnGa, and Co—Ni—Al.
 16. The adjustableannuloplasty ring of claim 9, wherein said ring dimension is aseptolateral dimension.
 17. An adjustable annuloplasty ring comprising:a first shape memory member configured to transform said annuloplastyring from a first configuration having a first size of a ring dimensionto a second configuration having a second size of the ring dimension,wherein said first size is less than said second size; and a secondshape memory member configured to transform said annuloplasty ring fromsaid second configuration to a third configuration having a third sizeof the ring dimension, wherein said third size is less than said secondsize.
 18. The adjustable annuloplasty ring of claim 17, wherein saidfirst shape memory member is configured to change shape in response tobeing heated to a first temperature, and wherein said second shapememory member is configured to change shape in response to being heatedto a second temperature.
 19. The adjustable annuloplasty ring of claim18, wherein said first temperature is lower than said secondtemperature.
 20. The adjustable annuloplasty ring of claim 18, whereinsaid second temperature is lower than said first temperature.